history and society

Industrial revolution

2009-12-13T21:59:00.000Z

Challenge the belief in this as a special time when technology changed.

The history of freedom

2009-11-30T21:17:00.035Z

This post is under construction

I apologise for the lack of progress on this post. I started off thinking I understood the issues and it would be a fairly simple thing. However, it has become clear that I do not really understand 'freedom' nor how it has evolved over the millennia. As far as I can see, no one has ever really discussed the history of freedom per se before. The issues are more complex than I realised, and the information I need is not presented in any kind of easily digestible form. As an exercise, I checked the indices of about ten books on 'world history', and only one of them (David Christian's Maps of Time) even mentioned 'freedom' at all. Although you do not see much activity on this blog, I am beavering away behind the scenes, toying with theoretical ideas, and reading or re-reading anything that could help.

As the last glaciation was coming to an end, around G 1500-1550 (13,000 to 11,000 years ago), hunting peoples followed reindeer and other herds into the spaces left by the retreating ice sheets. Some of them camped in the caves of Creswell Crags, in the heart of Britain. Here they made engravings on bone and on the rock walls. The engravings included an ibex, a species not known to have lived in Britain but present further south, which suggests that these ice-age humans wandered freely over the 750 miles between Britain and Spain or southern France. This was especially feasible because sea levels were low and Britain was still joined to the rest of Europe by dry land.

The humans of G 1500 were incredibly free. They lived in a world without governments or police, without national boundaries or customs posts. They could make their camp-sites wherever they liked. Their journeys north and south would have been quite seamless, since the modern countries of Britain, France or Spain of course did not exist in any shape or form. The hunting/foraging lifestyle, living off the land, made it natural to roam far and wide, and there was absolutely nothing to stop them. They had little reason to get attached to any particular place, for their way of life could be practised as easily in one place as another--the only constraint was their knowledge of local plants and animals, and of where to find the vital resources of water and stone.

How things have changed. People in G 2081 (today) are tied to the places where their jobs, homes and possessions are to be found. Planning rules and immigration controls restrict where they can build and make their homes. Their efforts are taxed, and their behaviour is constrained by countless laws, for example obliging them to send their children to school and shutting off most of the countryside as other people's private property. This is not to mention the wholesale deprivation of their liberty if they harm others or offend against the moral code. And the level of restraint seems to be intensifying, as laws multiply and people are subject to ever more comprehensive forms of surveillance.

How and why did we get from the total freedom of the first humans to the many controls and restrictions on freedom of modern times? Has freedom steadily diminished between then and now, or was it, say in the form of serfdom and slavery, even more restricted at certain times and places than it is for us today?

First, we need the definition of freedom. Here it is:

The freedom of a sociological actor is the fraction of the actor's behaviour and experience that is subject to the actor's own choice and decision-making.

Notice in this definition the reference to 'experience' as well as 'behaviour'. This captures the notion that people who are exposed to things (such as cold or hunger) they would not choose for themselves are not completely free. The stoic philosophers spoke of the sphere of choice. The thing that is within everybody's sphere of choice is their own mental life. Pretty much everything else, including your own body, is outside the sphere of choice because you are generally powerless to prevent it, say, catching disease, growing tired, or being imprisoned. Nevertheless, some people--the extremely rich, mainly--have more control over at least some of these issues than other people do (e.g. money can buy better doctors and better lawyers). They enjoy a wider sphere of choice with respect to what they experience, and are therefore more free--both intuitively, and as implied by the above definition.

Nevertheless, the 'experience' element of this definition of freedom is really only needed for advanced treatments. In the introductory discussion of the present post, we can focus on the primary component of freedom, which is behavioural choice.

There are three ways in which choice can be restricted: socially, economically and politically.

Socially, we are constrained by our affection and respect for those with whom we share a sense of identity--our family, our friends, our neighbours, our compatriots. We modify our behaviour in order to fit in and be considerate.
Economically, we are constrained by the need to reciprocate for the benefits we receive from exchange partners;for example, as employees we need to attend work between certain hours and take direction from our employers in order to receive our wages.
Politically, we are constrained by the laws and commands of those in authority and their representatives--police, military, officials.

We can say that we are constrained socially by what we ought to do, economically by what we are obliged to do, and politically by what we have to do.

Of these, social constraints are the most limited in that they only work with those we care for, i.e. with friends, in the technical sense, who are quite few in number. Political constraints are potentially unlimited in that they are imposed by strangers on strangers, and everyone is at least a stranger.

A certain amount of freedom has to be given up when people live together because there are bound to be disputes. One person's goals will clash with another person's goals, and the result will be conflict. To maintain society intact, people must be prevented from choosing their behaviour in a completely self-interested manner. Otherwise, society will rupture, as people get away from those with whom they are in conflict.

The effect of constraints on freedom is to ensure that a certain proportion of people's goals are externally imposed, by society in general, and so cannot give rise to conflict. If people have no choice over their goals, they cannot come into conflict. That is, there can be no conflicts of goals when people either completely care for each other (social constraints), are completely beholden to each other for their material welfare (economic constraints), and/or are completely under the control of an external authority (political constraints). Conversely, conflicts will be at a maximum when people do not care for each other, do not depend on each other for their livelihoods, and are subject to no external control.

Let us define the following:

(p) = probability of conflict between a random pair of sociological actors

n = scale (i.e. number of distinct actors encountered per unit time)

z = span of choice restriction (i.e. number of people one cares for, number of people with whom one has economic dependencies or number of people under control of the external authority)

λ = fraction of choices that are not free (=1-freedom, where freedom is defined as above)

d = disputes per actor per unit time

A given actor encounters n other actors per unit time. Of these z will be under a shared constraint of restricted choice, and (n-z) will be under no such constraint. (We are assuming n<z. We will discuss what happens if this is not the case shortly.)

With those actors who are under no shared constraint on choice, the probability of a dispute is simply p. Therefore, the number of disputes is (n-z)p.

With those actors who are under a shared constraint on choice, only a fraction (1-λ) of possible choices are capable of generating a dispute. We might guess that the probability of a dispute is therefore not p but (1-λ)p. In fact, this is not exactly true, but it is a good approximation provided the chances of a dispute with any other particular actor are quite small--something we will assume to be the case (people get on fairly reasonably with each other most of the time). (The following paragraph, which can be skipped, shows why p(1-λ) is a reasonable approximation if p is small.)

Suppose that each actor has goals with respect to n different issues. Let b be the probability that the goals of a given pair of actors, with respect to a given issue, do not clash. Then the probability of a dispute between two actors, i.e. the probability that they clash over at least one issue, is

p=1-bⁿ

Now suppose that a proportion λ of goals are shared, i.e. a proportion κ = 1-λ of goals are not shared. Only the κn unshared goals can result in a clash, so the probability of a dispute is changed to

p'=1-b^κn

Disputes are relatively rare, so we can assume that the probability of a pair of goals clashing is quite small. Hence, b, the probability of a pair of goals not clashing is quite close to 1. Therefore, let us write b as

b=1-ε, where ε is some small number

Then we can rewrite p and p' above as

p=1-(1-ε)ⁿ ≈ 1-(1-nε) = nε
p'=1-(1-ε)^κn ≈ 1-(1-κnε) = κnε = κp = (1-λ)p

Thus, provided the probability of a dispute is small, then it is true that, if a fraction λ of choices are unfree, the probability of a dispute is reduced to a fraction (1-λ) of its baseline value.

Therefore, the total disputes per person per unit time is

d = (n-z)p + zp(1-λ)

= (n-zλ)p

Now, a society can only support a certain level of disputes per person per unit time. Above this level, the society will break up and fly apart as people find that it is impossible to live together. We may therefore define:

d₀ = maximum level of d, above which society cannot exist

(This can be regarded as a constant of human nature.)

We thus have

d₀ ≥ (n-λz)p

⇒ n ≤ d₀/p + λz

Each society therefore has a maximum scale that depends on the values of λ and z in that society. If we indicate this maximum scale by n*, we have

n* = d₀/p + λz

We can write this as

n* = n₀ + λz

where n₀ = d₀/p is the maximum scale of a society whose members are completely free, i.e. where λ or z (or both) equals 0.

What is the value of n₀? It is certainly not very large as, even in family-level societies, people sometimes have to suppress their personal wishes, at least to a small extent, in order to get along. If people's choices were not restricted at all, a society could not be any larger than the family level and might have to be much smaller. Could even a pair of people stick together, in a minimal society, if each person did as they pleased? If not, it suggests that n₀ might be as low as zero. That is, in the case of complete freedom, the only society possible would be a society of one. (In a society of one, scale would be zero because the lone member of the society would never encounter any other actor.)

Hmmmmmmmmmmmmmm

Human freedom is the subject of a perpetual battle between opposing trends.

On the one hand, freedom is steadily diminished by ever-expanding governmental surveillance and control.
On the other hand, freedom grows in the form of new possibilities and opportunities created by ever-expanding human capabilities.

Technology is crucial to this paradoxical evolution. New technologies extend the reach of governments at exactly the same time as they extend the ease of movement of their subjects. The internet allows people to communicate with each other directly, thus breaking the information monopoly of governments and media corporations, yet on-line activity is readily monitored and leaves almost un-erasable traces for law enforcement to collect.

The post is on hold because I am stuck - on trying to work out mathematically what I mean by freedom in its various guises, and why freedom should vary.

Human freedom diminishes with time, in the sense that people are increasingly subject to surveillance and control by a political apparatus. Twenty first century people, especially in the more developed countries, are the least free that humans have ever been. However, they still have more freedoms than will be enjoyed by the people of the future.

Fortunately, this diminishing freedom in the political sphere is offset by technological growth, which offers possibilities and opportunities, such as long-distance travel, that people perceive as new freedoms. In this sense, twenty first century people enjoy vast freedoms unknown to their ancestors, but they are still very limited and circumscribed in comparison to how humans will be in time to come.

There is an equilibration process, or arms race.

Historic ages

2009-11-30T21:15:00.061Z

It is conventional to divide prehistory into stone, bronze and iron ages.

In modern times, this scheme is attributed to Christian Jürgensen Thomsen (G 2072-5, 1788-1865). He recognised the pattern while classifying objects for the National Museum of Denmark.

However, the Roman poet Lucretius (Titus Lucretius Carus, c. G 1997-8, c. 99-55 BC), in his scientific poem On the nature of things, wrote that humans first used stone for their tools, then copper and finally iron (Book 5, lines 1281-1296). Lucretius's reference to copper can be taken as shorthand for bronze (which is 90 percent copper).

Before Lucretius, the Greek poet Hesiod (c. G 1970, 750 BC) described five ages, in the following order: gold, silver, bronze, heroes, and iron. Here, the age of heroes stands out as not being named after a metal. It seems to refer to what, in modern reckoning, would be the late bronze age/early iron age, a time of warfare and social breakdown in the Greek peninsula. As for gold and silver, Lucretius also noted that people were using these metals in what for him was the copper age, but he said they preferred copper because it could be worked more easily than the two precious metals.

These three basic ages -- stone, bronze and iron -- have been further divided and refined in various ways.

The stone age, for example, is divided into the old stone age (palaeolithic) and the new stone age (neolithic), while the old stone age is itself divided into the upper, middle and lower palaeolithic (with the upper being the most recent part). Between the stone and bronze ages is recognised to be a copper age, known as the chalcolithic or eneolithic.

Terminology varies between the archaeological traditions of different regions. For example, in African archaeology, the upper/middle/lower palaeolithic tend to be called the late/middle/early stone age. Meanwhile, in Europe there is recognised a mesolithic between the palaeolithic and neolithic; although 'mesolithic' literally translates as 'middle stone age', this is not the same as the African middle stone age, which refers to the middle part of the palaeolithic. In some regions outside Europe, the equivalent of the mesolithic is called the epipalaeolithic.

The history of fully modern humans begins with the upper palaeolithic (or whichever term is preferred in other regions, e.g. late stone age in Africa).

What age are we in today?

We continue to use iron. The contents of the average cutlery drawer, for example, are generally made of iron (or more precisely steel, which is over 95 percent iron and has been the predominant form of iron since antiquity). On the other hand, we have introduced a variety of other materials to replace iron in various applications -- notably plastics, which future archaeologists will no doubt find clogging up excavations dating from our period. So this could be the plastics age. Alternatively, some suggestions pick out other features of our time, labelling this the space age or the information age.

To understand the significance of these 'ages', there are two facts we need to consider:

The 'ages' started and ended at different times in different places. In south-west Asia (Iraq), the start of the bronze age was around G 1840 (c. 4000 BC), while in western Europe it was around G 1920 (c. 2000 BC).

The technologies were not confined to the ages named after them, but could first appear well beforehand and continued in use long afterwards. For example, iron was already known about in the bronze age, and, during the iron age, bronze continued to be favoured for some items, such as statuary and clothes pins. Similarly, particular stone tool types (lithic modes) are known sporadically from times long before they came into widespread use, and stone tools continued to be made into the bronze age.

Taking the second point first, it is clear that the discovery of the technology did not in itself turn it into a prominent part of everyday life. Phasing out one technology and phasing in the next only occurred after a lengthy delay.

The reason for this is that the whole of society revolved around these fundamental technologies. It was not a question of putting down one type of tool and picking up another. The entire political, economic and social structure had to be rearranged.

Consider the change from stone to bronze.

(Economic issues) Late stone age people did not generally make their own axes - they were produced by specialists and were traded, sometimes over hundreds of miles. Obviously, the end users had to provide something in return, and so particular goods would flow back towards the makers of the axes. What represented a fair and feasible exchange for a given type of axe would have become established through experience. The end-users and axe-makers did not necessarily meet face-to-face but the axes may have passed through the hands of one or more intermediate traders, who not only saved everyone a long journey but may have played a useful role in swapping the goods the end-users had to offer for other goods more desirable to the axe-makers. To shift from stone to bronze, this network had to be dismantled and a new one constructed - one that now linked the end-users with the people and places where bronze was produced. This represented a problem for the stone axe-makers and for the stone axe-traders. New traders had to set themselves up, and the types and quantities of goods to be exchanged for bronze axes had to be worked out. So this technological shift required all involved to adjust their livelihoods and make contact with different parties, while some (the stone traders) were likely to lose out as others gained.

(Political issues) Bronze weapons were far more effective than stone weapons. So unless stone age chiefs were quick to get the new technology they were apt to find themselves being overpowered by new warlords, perhaps people they had once dominated but who by luck or judgement got bronze before they did. Not only did vagaries in the obtaining of bronze affect the balance of power, but the superior qualities of bronze allowed warlords to project their authority over much larger areas than before, though that would not be achieved without a fight.

(Social issues) Stone tools were not just utilitarian objects. They had a place in ritual and religion. This is apparent both from the appearance in burial mounds of stone axes that were clearly ceremonial objects, too good for everyday use, and from studies of contemporary stone-using societies. The shift to bronze thus required a transformation of religious thinking or more generally of cultural ideas and practices. In his classic essay Steel Axes for Stone Age Australians, the anthropologist Lauriston Sharp described how, among Australia's Yir Yoront aborigines, only senior men knew how to make stone axes, and this allowed them to maintain their authority over women and junior men, who had to borrow an axe from a senior man whenever they needed one. However, missionary workers gave the aborigines steel axes, without preferring senior men over the others - indeed senior men avoided the missionaries and tended to lose out in the distribution of steel axes. This removed the basis of the senior men's authority and led to a breakdown in the aborigines' whole social order. Similar social transformations may have been triggered by the switch from stone to bronze.

Thanks to the above issues, there was much inertia or resistance to the historical change from stone to bronze. Not only were the adjustments going to be painful but people had little way of knowing whether it would be worthwhile in the long run. So they avoided going down that route in the first place.

Nevertheless, experimentation continued in the background, and the properties and possibilities of bronze became increasingly familiar until it could no longer be resisted. When the changeover occurred it was inevitably rapid. It was not possible to combine some aspects of stone-based society with some aspects of bronze-based society, because the two were fundamentally incompatible. These were distinct eigenmodes and people had to switch from one to the other wholesale.

The switchover was, however, heavily contested. There was war, impoverishment and cultural disruption as the ambitions of those who stood to gain from bronze clashed with the fears of those who stood to lose out, while trading networks collapsed and relations between members of society were fundamentally renegotiated.

In short, the stone-bronze transition was accompanied by a dark age, when the political, economic and social institutions of the stone age were broken down to make way for the building of new political, economic and social institutions more suited to the conditions of the bronze age. This is in accordance with the phoenix principle.

What is true of the stone-bronze transition is true of other transitions. They were also brought about via dark ages. Within the stone age, it is possible to detect dark ages mediating the transitions to mesolithic and neolithic society. And this is also what lies behind Hesiod's identification of an 'age of heroes' between the bronze and iron ages. The age of heroes was a time of violence and warrior culture, when kings and armies thrashed out a new geopolitical landscape for the iron age, and learned how to organise and fight with their new weapons.

We can now return to the first point, i.e. that technological change occurred thousands of years earlier in some places than in others.

The traditional view would be that new technology just took a long time to diffuse say from the middle east to northern Europe, and that this would be evidence of the lack of contact between ancient societies.

We now see that the delay has nothing to do with societal contacts or the flow of ideas. In fact, ancient societies were in frequent contact, and information took just years, not thousands of years, to get from one place to another. The problem was that societies needed to undergo vast political, economic and social changes if they were to exploit the information that was coming through. It was the sheer magnitude of the changes, not the difficulty of communication, that slowed down technological uptake.

It is the same as in Africa today. Africa is exposed to advanced industrial technologies almost as soon as they come into use elsewhere, but Africa is nonetheless finding it difficult to transform itself politically, economically and socially so as to incorporate the technologies fully into its way of life.

It is not only underdeveloped societies that may find it hard to transform. Sometimes societies lag behind precisely because they are already successful and have little incentive to change.

At the time of the bronze age, Egypt lumbered on, not taking up the bronze technology that was making great headway among the fragmented city states of Mesopotamia. Egyptian society was already highly adaptive and its vested interests were powerful enough to fend off changes that might challenge their social position. In a similar way, mighty and monolithic China lagged behind as the fragmented polities of Europe made great technological advances in the eighteenth to twentieth centuries. Both Egypt and China suffered because of their conservatism, though both eventually accelerated into the new technological era.

Thinking about history in terms of technological ages therefore has both good and bad points:

It is 'good' in that the various technologies genuinely stand for distinctive configurations of social institutions, which, because of their mutual incompatibility, changed wholesale from one to the other.
It is 'bad' in that the emphasis on technology may fail to convey the important point that these ages involved far-reaching political, economic and social, not just technological, transformations.

As labels for major societal eigenmodes, the stone-bronze-iron ages, with their subdivisions, are too convenient to give up. We just have to remember that they are a shorthand for what were ultimately sociological rather than technological revolutions.

Nevertheless, the difficulty of deciding whether we are still in the iron age or, if not, what age we should call this, indicates that the age concept is not abstract and generalised enough to cover ongoing technical and societal change. We need something more formal and theoretical.

Such an improved measure is a society's total technology complement or inventory. Rather than using just one technology to stand for the total way of life of a society, we can consider all the technologies that the society incorporates into its way of life -- i.e. not just 'bronze', say, but weaving, needlework, pottery, roof-thatching, bow-making, net-making etc.

The 'inventory' concept provides a more nuanced characterisation of technological change than the blunt division into stone/bronze/iron ages. It allows for finer gradations of technological level and it can be immediately generalised to current and future technological levels. We do not need to argue about whether this should be called the space age or the plastics age; we merely tot up the total inventory of modern technologies. Unlike the 'age' concept, the 'inventory' concept also decouples technology from an explicit dependence on time, and this is more consistent with the fact that technological advances do not occur everywhere simultaneously, even among societies that are in contact.

I will return to a more detailed discussion of inventory in a later post. The main purpose of this post has been to get a handle on the significance of technological ages -- i.e. that they are good rules of thumb, which have some theoretical justification behind them.

Technological evolution

2009-10-15T19:36:00.246Z

We need a measure of technological sophistication.

Technology changes through history, and technological sophistication is closely related to scale and societal eigenmode.

The internet, for example, makes possible and is made possible by the high scale of the modern world.

It should be obvious that the internet makes the modern world possible. Consider the direct impact on many businesses if their web and email facilities were suddenly shut off, and consider the indirect impact on many others.
As for the modern world making the internet possible, imagine a group of, say, a hundred idealists who decide to cut themselves off on a desert island. Could they produce or maintain all the familiar internet facilities like Google, Amazon and Wikipedia? Obviously not. Even if they took this technology with them, they would soon fall behind what was happening in the outside world, where thousands, even millions, of people are continually advancing the relevant services and underlying software.

In order to talk comparatively about technological change, we need a uniform way of describing the degree of sophistication of any given technology. This has to be applicable to everything from a stone axe to a Saturn V rocket and beyond.

Technological sophistication reflects four factors relating to the creation of an artefact instantiating that technology:

The sophistication of the inputs or precursor processes and materials.
The amount of effort needed for preparation (e.g. assembling the materials in one place).
The amount of effort needed for actually producing the artefact.
The amount of skill required.

The higher the skill, the higher the effort of preparation and production, and the higher the sophistication of precursors or inputs, the greater the sophistication of the technology.

A crude stone axe requires no input except a stone, which is about as unsophisticated as one can get, and minimal preparation. It may take some skill but this is relatively easily acquired, and the process of production may involve only a few minutes of effort.
A space rocket has very sophisticated inputs, including specialist plastics and alloys, complex microelectronics, and a large ground-based infrastructure for mission control. Preparation and production may take many years of effort by many people, and they will be drawing on an extensive education, from kindergarten through university to specific on-the-job training.

We can reduce the four factors to a common form by considering them in terms of time resources (also known as effort), i.e. the number of people involved in each activity multiplied by the amount of time each person contributes. Specifically, we define technological sophistication as equivalent to total time resources to produce the artefact:

t = t_m + t_p + t_s +
∑
i t_i

where

t = total time resource to produce artefact ( ≡ technological sophistication)
t_m = time resource for actually making the artefact
t_p = time resource for preparation
t_s = time resource for skill acquisition
t_i = total time resource to produce input i ( ≡ technological sophistication of input i)

Technological sophistication therefore has units of person-seconds (or equivalently person-hours, person-days, person-years, whichever is most suitable). Note that technological sophistication is a characteristic of an artefact, not of a society or of a period in history.

Technological sophistication can be thought of as the amount of time it would take one person, starting from scratch, to manufacture the artefact in question, including all its precursors and materials. If the artefact were, for example, a Saturn V, the person would have to begin by learning basic geology and making a spade or pick in preparation for mining the ore to produce the metal from which the rocket's parts would eventually be constructed. The technological sophistication of the rocket could amount to many human lifetimes.

The actual time resources going into the creation of an artefact are not, in general, equal to the theoretical time resources used in the above definition of technological sophistication. This is because few artefacts are made starting from scratch. Instead, effort is amortised over many artefacts.

For instance, once a digger is available for mining ore, it can be used on many projects, not just to produce the one Saturn V. The time resources absorbed by producing the digger are in reality shared across many projects, and the Saturn V is responsible only for a small fraction of that effort.
Similarly, if multiple copies of an artefact are produced, the effort for skill acquisition, and possibly some of the preparation, does not need to be repeated. The skill acquisition and preparation time resources per artefact are therefore a fraction of what they would be for just one artefact.

Nevertheless, it makes sense to define technological sophistication as if one were starting from scratch while producing only enough of everything to manufacture one final artefact, even though that does not happen in practice. It is this definition that gives the truest account of what goes into making an artefact.

Consider writing a letter on a computer versus writing it with quill pen and parchment. The effort involved in each case may be about the same (e.g. it could take an hour to produce the letter either way). This is also true of preparation (switching on the computer, trimming the quill pen) and skill acquisition (learning to type, learning proper calligraphy)--the effort may be about the same in each case. Even the time resources devoted to the inputs might be similar if the time to build a computer is about the same as the time to prepare a piece of parchment from animal skin. Therefore, if we considered only the actual time resources going into the modern and medieval letters, there would seem to be no difference in technological sophistication. However, there obviously is a big difference in technological sophistication, which is reflected in the fact that a lot more effort and knowhow went into the development of the modern computer than ever went into the development of parchment and quill pens. This is what our definition of technological sophistication captures by assuming one starts absolutely from scratch.

Consider also that one person probably could produce a parchment letter from scratch (e.g. starting by tanning the goatskin and mixing soot and egg white to make the ink* etc.). However, to make a computer starting from scratch (i.e. beginning at the level of mining the ore) would take a lifetime, or probably several lifetimes. The time resources going into a computer are so high that, to make computers feasible/affordable, the time resources have to be amortised over many units, both for the final artefact and for the components from which it is built. This industry can only survive if it is done on a large scale, serving a large customer base. In this respect, medieval society was neither populous nor connected enough to support computing, and parchment-based letter writing technology was all that was feasible.

*This is merely illustration, not an accurate description of how to make medieval ink.

To demonstrate this definition of technological sophistication, I will calculate the changing sophistication of cutting tools, from the stone age onwards.

I cannot provide absolutely accurate values of technological sophistication, especially for the more complex technologies. This would require a vast amount of research. The figures given below are only estimates. My main purpose is to show the definition of technological sophistication in practice.

The first cutting tools used by humans were made of stone (=lithics). The tools of the palaeolithic and mesolithic (old and middle stone ages) can be classified into five lithic modes, reflecting increasing levels of sophistication (see Grahame Clark, World prehistory: a new outline, 2nd edn [1969]). The cutting tools of the neolithic (new stone age) were of higher sophistication again. After this came the successive increases in sophistication of copper, bronze and finally iron or steel tools.

Mode 1 stone tools involve the creation of a cutting edge by the application of a few sharp blows from another stone. This requires skill, but not much effort, and little attention is paid to the final form, which is rough and ready. The tool may either be the stone or one of the flakes chipped from it. Sometimes the tool is 'retouched' by chipping off a few small flakes to restore a cutting edge after it has been blunted or broken in use.
Mode 1 stone tools: typically prepared with just a few blows, ad hoc in size and shape

Mode 1 tools were already in use with early hominids in Africa, 2.5 million years before the appearance of modern humans. Some of the tools used by Australian aborigines, who are fully modern humans, continue to belong to this most basic category.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	None	0
Skill acquisition	Ten minutes to pick up the basic technique, though performance would improve with practice	600
Preparation	5 minutes to select a suitable stone and hammer stone. Any kinds of stone lying around would be suitable, provided they were of reasonable size and shape.	300
Manufacture	1 minute to knock off a few chips	60
TOTAL		≈ 1000

Mode 2 stone tools require at least twice as many blows as a Mode 1 tool, and they are made to take a definite, standardised, symmetrical form, that of the classic hand axe. Instead of chipping with another stone, a soft implement of wood, antler or bone is typically used, often with pressure flaking, to provide fine control over the shape. The removed flakes are not used.

Mode 2 stone tools: chipped all the way round with a soft hammer (wood, bone) to achieve a definite symmetrical form, requiring at least a dozen blows

Mode 2 tools were in use with pre-human hominids from about 1.5 million years before the emergence of humans. The technology developed in Africa and was carried into Europe and Asia by the pre-human hominids that colonised these regions from around 1 million years ago. Again, Mode 2 tools have continued in use with the Australian aborigines.

-- Key innovation --

Specialised ancillary tool (wood etc. hammer); aim of producing a repeatable, pre-conceived form.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	The bone/wood/antler flaking tool needs to be sourced and prepared, cutting it to the right length and maybe shaping it a bit. Perhaps twenty minutes.	1200
Skill acquisition	It should be possible to get the technique (from sourcing the stone and flaking tool to the design of the axe) in an hour.	3600
Preparation	A more specific size, shape and type of stone is required. Going to a likely site and selecting a suitable stone might take about half an hour.	1800
Manufacture	More blows are required and more careful attention, in order to get the symmetrical shape. Perhaps 5 minutes.	300
TOTAL		≈ 7000

Mode 3 stone tools involve the Levallois technique, in which a stone core is first carefully prepared and then a single large flake is struck off from it with a sharp blow. In contrast to Mode 2, where the shape emerges gradually, allowing some trial and error, this technique requires a thorough understanding of how flint fractures and an ability to picture in advance the flake that will be produced. Preparation of the core requires a hundred or more shaping blows before the final blow that removes the flake. However, the precise shape of the flake is not particularly standardised.

Mode 3 stone tools: struck with one movement from a carefully prepared core, requiring around a hundred preliminary blows along with the expertise and imagination necessary to envisage how the stone will fracture at the last critical blow

Mode 3 tools are associated with the near-human Neanderthals and were in use from about 200,000 years ago. The first modern humans also sometimes used Mode 3 tools, and indeed the Australian aborigines have never used anything more than Mode 3.

-- Key innovation --

Extensive preparatory work during which finished item is not apparent.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	Again a special tool is used for flaking. To prepare it: twenty minutes.	1200
Skill acquisition	A period of practising more basic techniques would be needed to develop the necessary understanding of stone's characteristics. One 8-hour day.	28,800
Preparation	Special types of stone, similar to Mode 2, would be required. Fetching time: 1 hour	3600
Manufacture	A long period of shaping the stone is required before striking off the final product: 10 minutes	600
TOTAL		≈ 35,000

Mode 4 stone tools are based on long, narrow blades with two sharp edges. These are struck from a core whose preparation is more complicated than for Mode 3, requiring some 250 blows with a bone rather than stone hammer, but then yielding five times as many tools from one block of stone. Blades are also versatile. For example, one edge may be blunted, to create a scraper, or the blade may be shaped into a burin, which has a sharp point and can be used to gouge holes in other materials.

Mode 4 stone tools: struck successively from a prepared core, having long sharp edges and possibly further shaped into specialised tools such as the burin (right), used for drilling holes

Mode 4 tools came into use among fully modern humans at the beginning of the Upper Palaeolithic, i.e. G 1 (c. 50,000 years ago). Whereas Mode 3 tool users stuck to stone almost exclusively, blade tools are associated with equal numbers of tools made from bone and antler. Only modern humans used Mode 4 tools, but not all modern humans used them, since the Australian aborigines and some extinct cultures of Southeast Asia never did.

-- Key innovation --

Preparatory work to produce savings downstream as many blades can be mass-produced from one core; creation of tools to make tools (e.g. burin is used for making holes in bone/ivory to produce needles).

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	Again a specialist hammer: twenty minutes	1200
Skill acquisition	Much practice is needed for genuine competence: two 8-hour days	57,600
Preparation	Greater care is needed in selecting the best stone (flint or similar). This might take a day (8 hours) to fetch. In reality, stone might be traded so that people would not have to find it themselves, but this is the sort of efficiency saving we ignore in the calculation of technological sophistication	28,800
Manufacture	The preparation of the core requires 250 blows and the blade is further refined after being struck: 25 minutes	1500
TOTAL		≈ 90,000

Mode 5 stone tools consist of microliths, i.e. small flakes of around an inch long, or less. They come in many precise forms, including triangle, rectangle, rhombus, trapezium, crescent and leaf-shape. They are not complete in themselves but belong to composite tools, such as knives, sickles, spears, harpoons and arrows, with several microliths being fixed into a bone or wooden handle or shaft using resin and possibly some kind of fibre.

Mode 5 stone tools: tiny microliths, chipped into precise shapes and stuck into wooden or bone handles/shafts, using resin and fibre, to produce composite tools such as an arrow (left, with trapezoid head) or harpoon (right)

Mode 5 tools appeared in Africa and India around G 475-875 (40,000-30,000 years ago). By G 1275-1675 (20,000-10,000 years ago) they were in use almost everywhere. There was, however, much more variation than for Modes 4 and below, with groups only a hundred miles apart favouring different shapes and styles of microlith. The greater sophistication of Mode 5 technology is also apparent from the way they were associated with simple 'machines' multiplying human muscle power, namely the bow and the spear thrower, both of which were in use by G 1475 (15,000 years ago, the bow may have been in use much earlier).

-- Key innovation --

Complex composite tools, themselves part of compound systems (e.g. bow and arrow).

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	The inputs are finished stone blades (the microliths). I will assume these have the technological sophistication calculated above for Mode 4 (90,000). Another input is string, for which I will conservatively assume a technological sophistication of 8 hours	118,800
Skill acquisition	Training is needed in sourcing resin, carving a stick to the right size and shape, and hafting the microliths to it. 8 hours	28,800
Preparation	Obtaining the resin and a suitable stick (the string and microliths are already available, having just been made). Half an hour.	1800
Manufacture	Carving the stick and attaching the microliths. Half an hour.	1800
TOTAL		≈ 150,000

Neolithic stone tools involve the imposition of a preconceived shape on a piece of stone. This is either by minutely detailed chipping, to create arrowheads and daggers, or by polishing, to create axes and hammers. In both cases, the form transcends the material of which it is made, in the sense that the object's function, rather than the behaviour of stone, is the primary driver. One is looking at an object that happens to be made of stone, rather than at a stone that has been hacked into a useful shape.

Neolithic stone tools: (not to scale) standardised forms determined by the intended function rather than by the properties of the stone, and involving either minutely detailed chipping to create arrowheads (left) and daggers (centre left), or polishing to create axeheads (centre right) and socketed axe-hammers (right)

Neolithic stone tools: (continued) a neolithic polished axehead, and the tool as it would have been used

The beginning of the Neolithic, and hence of tools like this, is synonymous with the beginning of farming around G 1600 (10,000 BC). The technique of polishing axeheads was perhaps suggested by the technique of grinding corn between two stones, where the stones became smooth as they rubbed against each other.

This technology emerged first in North Africa and the Middle East, and later in Europe, Asia and the Americas. It continued after the invention of metalworking, among people who could not afford or obtain metal tools. The above dagger dates from around G 1940 (1500 BC) and seems to have been inspired by bronze weapons.

Besides their practical purpose, polished axeheads had value as a medium of exchange and store of wealth. The clip below is of a hoard of axeheads found in a burial mound in Brittany, France, and shows they must have been produced in huge quantities.

-- Key innovation --

Form determined by function rather than by properties of underlying material.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	A suitable block of stone would need to be prepared as a grinding platform (8 hours). Animal hide would need to be obtained (by hunting) and prepared for binding the axe in a tool (4 hours). An initial set of stone tools would be needed for the carving and cutting tasks associated with these and subsequent activities (assume sophistication of Mode 4 tools: 90,000 person-secs).	133,200
Skill acquisition	The basic grinding/polishing technique could be picked up quite easily, although to create sharp, smooth and symmetrical axes would require longer practice. 2 hours	7200
Preparation	The hide is assumed available. Other parts to be sourced and fetched are: the stone to be polished, resin for gluing it in the handle, the handle itself, and one or more abrasives (sand) to be used in polishing. Total: 1.5 hours	5400
Manufacture	The stone would be roughed out by chipping then polished by rubbing against the platform, using successively finer abrasives to get the final smooth surface (1 day). It would then be mounted in the handle (1 hour).	32,400
TOTAL		≈ 180,000

Copper tools are made either by beating the solid metal into shape or by melting it and casting it in moulds. In a very few places, such as parts of the North American Great Lakes, copper can be taken from the ground in virtually pure form. However, most of the time it has to be extracted from an ore by heating. It thus requires an extra stage of transformation compared to the shaping of a stone. Yet unlike a stone, the molten metal can be cast into arbitrary forms, and once a mould has been produced, identical copies can be turned out one after the other. Copper is also less brittle than stone and, if broken, can be melted down and recast. Since copper is not nearly as common as stone, the widespread use of copper requires long-distance exchange between producers and consumers. Typically, the ore is refined close to the mine location then transported in the form of standardised ingots.

Copper tools: the metal is either beaten into shape with a hammer (e.g. spearhead, left; note the groove round the hammer stone for attachment of a handle), or molten and cast in a mould (e.g. axehead, right); the resulting copper tool (centre, reconstruction) can be neater and more compact than its stone equivalent

Copper tools: (continued) this is a classic oxhide ingot of the ancient copper trade; the ingot is 27 inches by 16 inches (70 cm by 40 cm) and weighs around 82 lb (37 kg); it is a convenient shape for carrying by two people
Copper and gold were the first metals to be worked by humans, beginning in ancient Iraq around G 1760 (6000 BC). Copper was in common use in Europe and Egypt by G 1860 (3500 BC). The reconstructed copper axe above belonged to Ötzi, the man from G 1870 (3300 BC) whose body was found in an Alpine glacier in G 2080:16 (AD 1991). Copper chisels were used in the building of the Giza pyramids around G 1900 (2500 BC). This 'copper age', also known as the chalcolithic (chalcolithic = 'copper-stone'), technology does not seem to have reached sub-Saharan Africa until G 1960-1980 (1000 - 500 BC).

The discovery of copper metallurgy is related to the invention of pottery, which meant that people were already experimenting with heating earthy materials in a fire. Pottery, in turn, could have been suggested by the practice of heating stone tools to give them strength; this may have led people to experiment with the effects of heat on other materials.

-- Key innovation --

Transformation of raw material (ore) whose properties are not those of the finished product.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	One input is the copper ore. This requires developing some knowledge of geology (4 hours), and then the actual location and extraction of the ore (8 hours). A set of stone tools would be needed for this (assume Mode 4: 90,000 person-secs). There is also a need for a pottery crucible and charcoal for the fire: assume 8 hours to make these.	162,000
Skill acquisition	It is necessary to understand the construction of a cast and the melting and pouring of the copper. 12 hours.	43,200
Preparation	The copper must first be produced from the copper ore. 8 hours.	28,800
Manufacture	A mould has to be made, then the copper poured. After the copper is removed from the mould, it requires tidying up and polishing. For this: 12 hours. Finally, the object needs to be mounted in a suitable manner: 4 hours.	57,600
TOTAL		≈ 290,000

Bronze tools are made from a mixture of typically 90 percent copper and 10 percent tin or arsenic. The metals are molten together and cast in a mould. Bronze is much harder than pure copper, and can hold a sharp edge. Tin-bronze is superior to arsenic-bronze, which therefore tends to be found only in early or less developed bronze industries. However, tin is even rarer than copper, so a tin-bronze industry presumes a well-developed trade network connecting the point where the ore is mined and refined with the regions where the bronze artefacts are to be produced.

Bronze tools: an alloy of copper and tin, bronze is strong than either and capable of carrying a sharp edge; varying sophistication is evident in both the amount of metal used and the complexity of the shape to achieve a given effect, here ranging from the flat axe (far left) to the same with small flanges that hold it more firmly in the handle (centre left), to the palstave axe with an attachment loop and shaped mounting area separate from the blade (centre right), and finally to the fully socketed axe (right)

The earliest bronze-working societies were in the areas of modern Turkey, Syria and Iraq, beginning around G 1860 (3500 BC). Bronze was in use in China by G 1912 (2200 BC), in north-western Europe by G 1930 (1800 BC), and in India and Egypt by G 1940 (1500 BC). In the Americas, metalworking, with gold, silver and copper, began around G 1980 (500 BC), and copper-silver and copper-gold alloys appeared around G 1993 (200 BC). Arsenical bronze did not appear until around G 2040 (AD 1000), and classic tin-bronze was only introduced by the Incas around G 2060 (AD 1475), shortly before the Spanish conquest. American pre-Columbian metalwork tended to consist of decorative and prestige objects, rather than tools or weapons.

Arsenic often occurs naturally in conjunction with copper, which would have facilitated the discovery of arsenical bronze and perhaps suggested the possibility of experimenting with other adulterating metals.

Styles of bronze artefacts evolved continuously, tending to become both more efficient and more mass produced in their appearance, as illustrated in the following clip.

I have participated in a couple of bronze-making workshops run by Dave Chapman. The first was to make a leaf-shaped sword based on one in the Pitt-Rivers museum; this was cast in a stone mould. The second was to make an early bronze age-style axehead, using the lost-wax technique.

Replica leaf-shaped bronze sword cast in stone mould
Replica early bronze age axehead made using lost-wax technique

-- Key innovation --

Combination of raw materials to produce substance not found in nature.

-- Sophistication estimate --

Factor	Discussion	Time resources (person-seconds)
Inputs	For the ores, geology knowledge is required - more than for copper as there are now two metals involved, so 6 hours. For locating and mining the ores, two 8-hour days. Again there is a need for a set of stone tools (assume Mode 4: 90,000 person-secs), and for a pottery crucible and charcoal for the fire (8 hours).	198,000
Skill acquisition	Similar skills are needed as for copper, but now two metals are involved. Assume 50 percent more effort: 18 hours.	64,800
Preparation	The metals need to be separately refined from their ores: 12 hours	43,200
Manufacture	The actual melting and pouring of the bronze takes relatively little time, but there is much work first in creating the mould into which the metal will be poured and then in cleaning up and polishing the object after it has been removed from the mould. For this, two 8-hour days. Finally the object needs to be mounted in a suitably carved handle: 4 hours.	72,000
TOTAL		≈ 380,000

Iron tools are usually made from iron combined with small amounts of carbon (up to about 2 percent), and possibly with other elements, to create various kinds of steel. In terms of hardness and sharpness, decent bronze can actually be superior to an average piece of iron. On the other hand, deposits of iron ore are relatively common, which means that, compared to bronze, the technology is less reliant on far-flung trade networks, and this makes it cheaper. Iron has a higher melting point than bronze (around 1500°C compared to 1000°C), so that refining or casting it requires more sophisticated furnaces and handling equipment. However, the metal can be worked at lower temperature in a forge. A sword, for example, can be made from a bundle of rods heated and hammered together -- the metal becomes soft enough to take on a new shape, but does not actually melt. Iron can also be welded. This involves causing two pieces of metal to fuse by the local application of intense heat.

Iron tools: made from a metal that is widely available but only melts at high temperature (although becoming soft enough at lower temperatures to be worked in a forge); iron is usually mixed with small amounts of carbon, and sometimes other elements, to create various steel alloys; iron and steel remain in common use for a wide range of tools; here are shown an axehead of around G 1980 (500 BC) from the Black Sea region (top left), a replica Roman sword (left), a Roman axe (centre), a modern axe (right), and a chainsaw (bottom right)

Iron was first produced in the period after G 1920 (2000 BC), in India, the middle east and east Africa, but this was only in small quantities and as a kind of novelty. Around G 1960 (1000 BC), iron came into widespread use, overtaking bronze as the material of choice for tools and weapons. This occurred first in the middle east and Mediterranean countries from Egypt to Italy. In central Europe, iron technology took off 10 g later, i.e. around G 1970 (750 BC), and in north-western Europe 10 g later still, i.e. around G 1980 (500 BC). Iron technology also became fully established in sub-Saharan African in this same period, G 1960-1980. Africa was unusual in that iron and bronze came into use there at around the same time, instead of a lengthy bronze age preceding the take-up of iron. Iron was not known in the Americas until after the Columbian contact (G 2060:17 = AD 1492).

The addition of carbon to iron, to make steel, was a fairly natural development, since carbon would previously have been used in bronze casting, where it prevents a skin forming over the molten metal. The carbon came from charcoal (85-95 percent carbon), which is obtained by heating wood in the absence of oxygen and burns at the high temperatures needed for melting metal. In a primitive foundry, with a charcoal fire force fed by bellows, there would be plenty of carbon dust floating around in the air, and early metallurgists probably could not avoid it getting into the mix.

Over the generations, the technology of iron-making has evolved in several ways. One goal has been to allow iron to be handled in larger quantities, while another has been to adjust the amount of carbon and other elements so as to produce iron/steel with varying qualities (in terms of melting point, malleability, rust-resistance etc.) suitable for performing varying tasks. One major innovation, the Bessemer process, was made only just over 6 g (150 years) ago, and iron-making patents continue to be taken out to this day. Steel remains important, although plastics and sophisticated composite materials are increasingly dominant.

-- Key innovation --

Iron-making was perhaps not as revolutionary as some earlier transitions between lithic modes or the first use of metals, but the development of the high-temperature furnace was a breakthrough.

-- Sophistication estimate --

Factor	Discussion	Time resources (seconds)
Inputs	A knowledge of geology is required: 4 hours. To obtain the ore (more widely available than copper ore): 4 hours. Also required are a crucible and high temperature furnace, along with charcoal fuel: two 8-hour days. Tools are needed to mine the ore and construct the furnace, for which assume a bronze package: 350,000 person-secs.	436400
Skill acquisition	The necessary skills include producing the high temperatures for melting iron, handling the molten metal, and understanding how carbon or other ingredients affect the metal's properties: 20 hours.	72,000
Preparation	The iron has to be smelted from its ore: 12 hours.	43,200
Manufacture	The work involves creating a mould, melting the iron, and polishing the cast object into a finished product: 2 days. Finally, it has to be mounted: 4 hours.	72,000
TOTAL		≈ 625,000

Summary

The following table summarises the technological sophistication of different types of cutting tools and the times at which they first appeared.

Technology	Sophistication	Appearance
Mode 1	1000	Pre-G 1
Mode 2	7000	Pre-G 1
Mode 3	35,000	Pre-G 1
Mode 4	90,000	G 1
Mode 5	150,000	G 500
Neolithic	180,000	G 1600
Copper	290,000	G 1760
Bronze	380,000	G 1860
Iron	625,000	G 1920

This chart shows growth of technological sophistication over time, based on the above table:

While these figures for technological sophistication are rough and ready, it is not surprising to see the kind of accelerating growth shown in the chart.

To make the numbers easier to write, it will be helpful to introduce some abbreviations. Thus, 90,000 person-seconds = 90x10³ ps = 90 kps, where ps is short for person-seconds and kps is short for kilo-person-seconds, i.e. 1000 person-seconds; similarly we can have Mps (mega=10⁶), Gps (giga=10⁹) and Tps (tera=10¹²).

To conclude, I want to make two final points:

Only modern humans have used tools with sophistication 90 kps and above (Mode 4 lithics and higher). However, this does not mean modern humans only use tools above 90 kps. Humans continued to use Modes 1-3 lithics alongside more sophisticated tools, while some groups, like Australian aborigines, did not use anything higher than Mode 3. On aborigine tool-making, see R. Foley and M.M. Lahr, 'Mode 3 Technologies and the Evolution of Modern Humans', Cambridge Archaeological Journal, 1997, 7(1): 3-36; A. Brumm and M.W. Moore, 'Symbolic Revolutions and the Australian Archaeological Record', Cambridge Archaeological Journal, 2005, 15(2): 157-175.
The adoption of a more sophisticated technology does not mean the abandonment of less sophisticated ones. At most, less sophisticated technologies become rarer over time, as more sophisticated ones are taken up. However, a relatively simple technology, such as a hammer, can be well adapted to its purpose and remain in widespread use despite massive growth of technological sophistication in other areas. Thus lower mode lithics continued alongside higher ones, neolithic tools continued alongside bronze, and bronze continued alongside iron. In principle, an astronaut landing on the moon could still pick up a pebble to fashion a Mode 1 tool for a purpose like prising open an equipment canister.

The first is the best

2009-08-18T22:13:00.047Z

In Works and Days, the ancient Greek poet Hesiod wrote that history began with a golden age, which was followed by a silver age, a bronze age, and finally the miserable iron age of his own time. He recognised that technological progress had occurred, but nevertheless believed that humanity's finest times lay in the past.

James Lovelock has called this grandfather's law, the belief that the old days were the best.

Yet there may be more at stake here than simple prejudice.

Suppose the world's population were asked to choose just one iconic building to stand for the whole of human architectural achievement. What would they vote for? The Taj Mahal, the Eiffel Tower, the US Capitol, The Forbidden City, the Parthenon, the Coliseum?

I think there is a good chance, when all is said and done, that they might settle on the Great Pyramid of Cheops. It is only within the last century that significantly taller buildings have appeared, and, while these may be more sophisticated than the Great Pyramid, they do not have its simplicity, nor are they likely to last as long.

That the Pyramid of Cheops should remain one of the world's largest and most iconic structures might seem extraordinary, considering it was built by people who were still using stone tools, but it illustrates a general principle: in many areas of human endeavour, first efforts are often the best.

The Apollo 11 landing, for example, will probably stand for all time as a highpoint of space exploration. People will one day return to the moon, and will eventually reach other planets and the stars beyond, and they will use technologies of unimaginably greater sophistication than those of Apollo. Yet whatever they do, the Apollo achievement will in some ways never be equalled -- going from a standing start to landing a series of crews on the moon within the decade, in the most primitive craft, and then returning them to earth without a single fatality.

Michael Collins, the Apollo 11 team member who remained in orbit while Neil Armstrong and Buzz Aldrin landed on the moon, has revealed that his biggest fear was that the lunar module ascent stage, which had never previously been tested under lunar conditions, would fail to fire, and he would have to return to earth alone. President Nixon had a speech prepared for this eventuality, in which he would have said that while Armstrong and Aldrin knew there was no hope of rescue they also knew their sacrifice would not be in vain. The speech was never needed, for the ascent stage performed flawlessly, and the mission was in every respect a triumph.

The observation that earliest examples are the best is encountered in all sorts of cultural phenomena.

The peak of Egyptian sculpture was achieved in the fifth dynasty, around the time the pyramids were being built (c. 2680 BC). This was never surpassed in the remaining two-and-a-half millennia of Egyptian history, though there was something of a renaissance in the eighteenth dynasty.
Experts on Mayan ceramics tend to note that the earliest designs are the most aesthetically pleasing and technically accomplished.
Drama in the modern sense began to develop in England from the mid-sixteenth century. Within forty years, it had already produced William Shakespeare, whose fame extends around the world. (A German friend once told me how he was shocked, when he was growing up, to discover that Shakespeare was not German.) In later centuries, Britain has produced other great dramatists, such as Oscar Wilde and George Bernard Shaw, but they are not in the same league.
The earliest known cave paintings, at Chauvet Cave in southern France (see right) have been described as "the best we know of Palaeolithic art...a confident peak from which later cave painting could only go downhill." (S. Oppenheimer, Out of Eden: The peopling of the world, [London, 2004], p. 121).

There are several possible reasons why the earliest examples of a given cultural activity should be superior to those that come later.

People have a need for mastery, to prove that they can do something. Once they have mastered whatever it is, their interest wanes. To land on the moon is a fantastic challenge that can inspire people to heights of daring and ingenuity, pushing contemporary technology to its limit. To land on it again is a humdrum task that people will get round to in due course when technology has advanced to the point that they can scarcely avoid it. Once people had built the Great Pyramid, they had proved their point. They would never build quite so ambitious a pyramid again, and before long they would stop building pyramids altogether.
The first patrons of a new cultural product are elites, who can afford to pay for quality. As time goes on, people ever lower down the social scale seek their own versions of the product, in imitation of their betters, and this demand is satisfied by mass production, skimping on materials and cutting corners. The earliest Mayan ceramics were rare items destined for royal usage. Later ones were cheap imitations to be found in every peasant home.
The first geographers to explore a new continent will be the ones to discover the biggest mountains, widest rivers and most spectacular views. Their successors can only fill in the details and will inevitably seem lesser folk. Similarly, the first people to explore a new cultural medium will access its finest opportunities, leaving only lesser achievements for those that come later.
In attempting to assert their own creative individuality, people distance themselves from the cultural forms of the past. When what was achieved in the past was perfection, cultural products that seek to be different and distant will end up looking flamboyant, bizarre or degraded.

The 'first-is-best' rule does not always apply, but even when it does not, the peak of achievement in a cultural activity often comes in a short burst, and involves a cluster of exceptional individuals. This was the finding of the anthropologist A L Kroeber in his book Configurations of Culture Growth, where he investigated cultural 'efflorescences' in fields such as painting, sculpture, philosophy and science, and in societies ranging from Greece and Rome to China and Japan.

The peak sometimes comes early in the efflorescence, and sometimes late. It is less common for the peak to come in the middle.
Wherever the peak comes, the people who are responsible for the peak, i.e. the highest achievers in the given field, tend to be contemporaries or nearly so. An outstanding example is the Italian Renaissance, where Raphael (1483-1520), Titian (1490-1576), Michelangelo (1475-1564)) and Leonardo da Vinci (1452-1519) were all active in each other's lifetimes.

As Kroeber argued, the clustering of talent shows that high cultural achievement is a sociological phenomenon, with a dynamic of its own, and is not dependent on the chance appearance of individual geniuses. In other words, phases of great brilliance, rather than being random occurrences, have sociological causes and are susceptible to sociological explanations. This means that they can and should be accommodated and accounted for in a theory of history.

In addition, the fact that humans' earliest cultural products can surpass their more recent ones teaches us something about our own situation: it is not because we are cleverer than ancient Egyptians or stone age hunters that we are more technically advanced. It is because we live at the latest moment in history, and are the beneficiaries of these ancient peoples' achievements. Rather than being in every way superior to those who inhabited the planet before us, we are in some respects their degenerate and less accomplished grandchildren.

Dating schemes

2009-08-18T20:41:00.094Z

(To those of you seeking a utility for converting BP and BC dates, scroll down to the applet at the bottom. You will need the JRE.)

In the west, we number years counting up from the birth of Jesus Christ. The year 2009 literally means in the 2009th year of Christ's age (although Christ is no longer around on earth, he is still, in Christian belief, very much alive). This is the 'Dionysian era', named after the monk, Dionysius Exiguus, who introduced it in 525. It became widespread when it was adopted by the Venerable Bede in the 700s.

One way of representing the Dionysian era is with the phrase 'In the Year of Our Lord' or the Latin equivalent 'Anno Domini'. Hence, we can say 'In the Year of Our Lord 2009' or 'Anno Domini 2009', abbreviated to AD 2009. Notice that the letters 'AD' should logically come before the year number, although it is now so common to write 2009 AD that the logical version might be considered almost pedantic.

The plaque left behind by the Apollo 11 astronauts reads: "Here men from the planet Earth first set foot upon the Moon, July 1969 AD. We came in peace for all mankind." Its author, William Safire, who later wrote a newspaper column on language and grammar, was mortified when he realised he should have put AD 1969 instead of 1969 AD.

While the term "AD" is standard in English-speaking countries, alternative but equivalent terms are sometimes used in other parts of the west. E.g. the French use "l'an de grâce" = "the year of grace".

To refer to dates before AD 1, we count backwards, using the term "Before [the birth of] Christ", abbreviated to BC.

The introduction of the Dionysian era greatly simplified the problem of dating, which until then had used a series of weird and wonderful schemes, such as naming years after the annually elected Roman consuls, or specifying the year of a particular king's or emperor's reign.

However, the AD scheme still has one quirk, stemming from the fact that there is no year 0 (1 BC was followed by AD 1). It means that BC dates cannot be treated as simply negative AD dates. E.g. the difference between 1 BC and AD 1 is just 1 year, not 2 years as it would be if we used the mathematics of negative numbers, saying 1 - (-1) = 1 + 1 = 2. Obviously, this is not really a problem, and we just need to remember that to calculate the year-difference between a BC date and an AD date, we add the BC date to the AD date, then subtract 1.

As the traditional Christian ethos of western society has been called into question under the influence of multiculturalism, some have wished to distance themselves from the terms AD and BC, which are closely tied to Christian doctrine. Instead, the terms Common Era (CE) and BCE (Before Common Era) are increasingly in vogue, especially in academic works, as replacements for AD and BC respectively. (In calendrical terminology, an 'era' is a date from which other dates are reckoned.) The CE/BCE scheme still uses the year of Christ's birth as its era, but this is treated as just a convenient point that happens to be in common use, and its significance is not explicitly acknowledged.

When we look at dates in the past, it can be difficult to get a real feel for their significance. Suppose we are told for example that two European countries fought each other in 1530 and again in 1580. Anyone with a reasonable awareness of history can probably conjure up a mental picture of the 1500s, such as the costumes and technologies of that century and some of its more famous personalities and events. However, unless one has made an in-depth study of the period, the distinction between the 1530s and 1580s is much hazier. The result is that the dates 1530 and 1580 sound quite close together, and subconsciously, we think of the two wars as following pretty much one after the other, and involving the same people and the same issues. This in turn reinforces our view of the past as relatively unchanging when compared to the kaleidoscopic unfolding of events in our own lifetimes.

A similar thing applies when we are told the Athenians did something in 600 BC and something else in 400 BC, or the Hittites arose in 1600 BC and their empire collapsed in 1200 BC, or people built Stonehenge in 3000 BC, extended it in 2600 BC and buried someone there in 2000 BC. The numbers are rather abstract and lose their meaning, while the Athenians, Hittites or users of Stonehenge tend to exist in our minds as though they are the same people, doing first one thing then another. However, the later Athenians, Hittites etc. were in fact the many-times-great-grandchildren of the earlier ones, and the earlier and later sets of people would not in general have had the same thoughts, attitudes or experiences.

To get a more realistic feel for ancient dates, I suggest the technique of mentally converting them into equivalent modern dates.

For example, when I read 1530 and 1580, I convert them in my mind into 1930 and 1980, e.g. imagining the 1530 people as being in the Depression Era, driving around in black sedans, and the 1580 people as watching 'Dallas' on TV while electing Ronald Reagan to the US presidency. Thus, I have a reasonable feel for the differences between 1930 and 1980, and this allows me to get a feel for the corresponding differences between 1530 and 1580, i.e. how personalities, costume and technology might have moved on, and how 1530 would have seemed quite old-fashioned from the perspective of 1580.
For dates spanning centuries, I think of the earlier date as equivalent to the corresponding period before our own time. For example, to the Athenians of 400 BC, people and events of 600 BC would have seemed rather like the people and events of AD 1800 seem to us. Similarly, if the Hittite empire spanned the period 1600 BC to 1200 BC, it is rather like an empire that lasted from AD 1600 to the present. Finally, the Stonehenge dates of 3000, 2600 and 2000 BC would correspond to AD 1000, 1400 and the present. This should make it apparent that the rebuilding of Stonehenge was not just the continuation of a general programme of construction, but was a fresh initiative, undertaken by people who may have known very little about the original builders and did not necessarily think about Stonehenge in the same way. Ditto the people who performed the burial - to them Stonehenge was already an ancient monument and the way they were using it may have had little to do with the intentions of its builders.

In archaeology, most dates are BC. Yet prehistoric artefacts do not usually come with absolute dates attached, and what archaeologists work out first, especially with techniques like carbon dating, is how old artefacts are. Obviously, ages can be converted into dates by subtracting from the present. However, this can seem artificial, and it often makes more sense to talk of something having happened "thirty thousand years ago", rather than to convert this into "28,000 BC", especially as archaeological age estimates are seldom accurate to the year anyway.

In light of the artificiality of BC dates for their subject, archaeologists have adopted the approach of specifying dates in terms of years 'Before Present', abbreviated to BP. So something that happened 4200 years ago would be said to have happened 4200 BP. Now, if BP were taken to mean literally 'before the present', something dated to, say, 561 BP one year, would be 562 BP the next year, and 563 BP the year after that. Evidently, this is totally impractical. Therefore, archaeologists have adopted AD 1950 as the standard 'present'. Years BP means years before 1950.

In my work on this blog so far, I have felt the need for a consistent and meaningful dating scheme, as none of the existing methods seems fully satisfactory. I am conscious of the pedantry and parochialism of the BC/AD scheme, but I balk at the clumsy and merely cosmetic CE/BCE alternative. I do not want to keep switching arbitrarily between BP and BC/AD, and would like a standard approach. However, when I am dealing with events of the upper palaeolithic and rough orders of magnitude, quoting BC dates seems rather absurd, but when I refer to recent historical events the use of BP would become equally nonsensical, as I would find myself saying "the first world war broke out in 36 BP" and people would wonder what I was talking about. Furthermore, BC and BP involve counting backwards, whereas it would be preferable to be able to count forwards. It would also be good if the dating scheme could help drive home the distinction between 1530 and 1580, or between 1600 BC and 1200 BC etc.

These thoughts have led me to the idea of expressing dates in terms of 'generations' from a given starting point.

Since I am concerned with history from the upper palaeolithic onwards, the starting point, or era, I will use is 50,000 BC.
The generation length I choose is 25 years. This has the advantage that it divides neatly into 100 years and makes it possible to translate easily from ordinary years to generations. Obviously the 'generations' I am using are schematised but they are not wholly disconnected from reality. We won't go far wrong if we imagine that people's oldest grandchildren are being born 2 generations = 50 years after their own births.
The idea behind using generations is that it should drive home the point that the Athenians, Hittites or Stonehenge-users of generation N were not the same people as the Athenians, Hittites or Stonehenge-users of generation N+10 or N+20, whatever it might be, but were their distant descendants.
The use of generations also gives smaller and more manageable numbers, and I hope it should be easier to visualise and make sense of the spans of time involved.

To convert a span of years to the equivalent number of generations, we divide by 25. Alternatively, if it is an exact number of centuries, we multiply the number of centuries by 4.

If we call the people living in 50,000 BC, generation 1, then to convert a date into a generation number, we calculate 1 plus the number of generations that have passed since 50,000 BC.

For example, the Last Glacial Maximum (LGM) was at about 18,000 BC. This is 32,000 years after 50,000 BC (50,000 - 32,000 = 18,000). In terms of generations, it is 32,000 ÷ 25 = 1280 generations later. (Alternatively, it is 320 centuries, and 320 x 4 = 1280.) Therefore, the people living at the LGM would be generation 1281 (because 1 +1280 = 1281).

When we calculate generation numbers for AD dates, we have to take into account the absence of a year 0. It was in the year AD 1 that 50,000 years = 2000 generations had passed since 50,000 BC. Therefore, AD 1 corresponded to generation 2001. For any general AD date, the total number of generations since 50,000 BC is 2000 plus the number of generations since AD 1. To find the number of generations since AD 1, we find the number of years since AD 1 and divide by 25. However, the number of years since AD 1 is not the number of the year but the number of the year minus 1. Thus, the year AD 2 was not 2 years after AD 1 but only 1 year after AD 1 (2 - 1 = 1). It was AD 3 that was 2 years after AD 1 (3 - 1 = 2). In the same way, it was AD 26 that was 25 years or 1 generation after AD 1. Therefore, AD 26 (not AD 25) was the beginning of generation 2002.

The generation number today is 2081, and it began in 2001. This is because AD 2001 was 2000 years or 80 generations (2000 ÷ 25 = 80) after AD 1, making 2080 generations since 50,000 BC.

Clearly, the generation number only narrows a date down to a 25-year window. All the years from 2001 to 2025 correspond to generation 2081, say. For my purposes, this degree of precision is usually going to be enough, even for historical dates. When talking about the colonisation of Australia or the discovery of agriculture, a 25-year window is obviously more than adequate. However, I am equally content to know, for example, that Columbus's discovery of America was in generation 2060 while the American Revolution was 12 generations later, in generation 2072. I am not writing narrative history so it is not necessary to be absolutely precise (even in ordinary history, the year is often good enough and it is not necessary to give the exact day).

Nevertheless, it would be desirable to be able to refer to the exact year if necessary. We can do this by including the phase, which means the position of the year within the 25-year generation. For instance, the 1st year within generation 2081 was AD 2001, so that AD 2001 has phase 1. The 2nd year within generation 2081 was AD 2002, which has phase 2. The 3rd year was 2003, with phase 3, and so on. This continues up to AD 2025, which will have phase 25. The next year, AD 2026, will be the 1st year of generation 2082, with a phase of 1 again.

We can now put all this together, to obtain some conversion formulas.

For these formulas we will use '%' to mean 'the remainder after dividing by' (or, for the mathematically savvy, 'modulo'). For example,

6 % 3 = 0
7 % 3 = 1
8 % 3 = 2
9 % 3 = 0
10 % 3 = 1
etc.

To convert from a BC/AD date to a generation date:

. . For BC dates:

. . . . generation = 1 + (50,000 - year) / 25
. . . . phase = 1 + (50,000 - year) % 25

. . For AD dates:

. . . . generation = 2001 + (year - 1) / 25
. . . . phase = 1 + (year - 1) % 25

To convert from a generation/phase to a BC/AD date:

. . For generation <= 2000 (less than or equal to 2000): . . . . year (BC) = 50,000 - (generation - 1) x 25 - (phase - 1) . . For generation > 2000 (greater than 2000):

. . . . year (AD) = (generation - 2001) x 25 + phase

We also need a notation for dates expressed in generations:

To represent an absolute date, we put a 'G' then the generation number, then a colon (':'), then the phase (if required). E.g. the year AD 1492, becomes G 2060:17, meaning it had phase 17 within generation number 2060.
To represent a duration, we put the number of generations, a colon, the additional phase (if required), then a 'g'. E.g. a duration of 65 years becomes 2:15 g, meaning 2 generations (50 years) plus an extra 15 years.

I will now provide some example dates, converted into generations (note: I have rounded some of the figures - e.g. 18,000 BC actually equates to G 1281, but I have rounded this to G 1280, since we are only talking approximate dates):

Event	Date
Event	Conventional	Generation
Beginning of upper palaeolithic	c. 50,000 BC	c. G 1:1
Last glacial maximum	c. 18,000 BC	c. G 1280
Invention of agriculture	c. 10,000 BC	c. G 1600
Founding of Egyptian 1st dynasty	c. 3100 BC	c. G 1876
Pyramid of Cheops	c. 2500 BC	c. G 1900
Beginning of bronze age	c. 2100 BC	c. G 1916
Beginning of iron age	c. 1000 BC	c. G 1960
Foundation of Rome	753 BC	G 1970:23
Birth of Christ	4 BC	G 2000:22
End of western Roman empire	AD 476	G 2020:1
Battle of Hastings	AD 1066	G 2043:16
Discovery of America	AD 1492	G 2060:17
Battle of Waterloo	AD 1815	G 2073:15
Apollo 11 moon landing	AD 1969	G 2079:19
9/11 attacks	AD 2001	G 2081:1
Today	AD 2009	G 2081:9

The generational dates should give a feel for relative timescales. E.g. the founding of the Egyptian first dynasty is around 200 g ago, compared to the 2080 g of the human story as a whole. The discovery of America is very recent at only 20 g ago.

It is also useful to note that one lifetime is approximately 3 g (75 years). So the period from the Battle of Waterloo to the first moon landing, which is 6 g -- meaning we would count grandparent, parent, child, twice -- is equivalent to 2 lifetimes laid end to end. From the building of the Pyramid of Cheops to today is 180 g or 60 lifetimes.

It is commonplace to note that life expectancy has been increasing, so it would not always be true that 3G = 1 lifetime. However, most of the increase in life expectancy is due to reduction in infant mortality not to people living longer. Even the Bible considers the typical lifespan to be 70-80 years. Bones of our most ancient, upper palaeolithic ancestors suggest they may have died younger, typically in their 40s, but the 'natural' human lifespan, under reasonably favourable conditions, seems to be around 75 years, as the Bible has it.

Here is an applet for converting AD/BC dates to generations and vice versa. (Instructions: (1) Enter a year into the year field, select AD, BC or BP; click "Convert to gen", and the generation number and phase appear in the generation fields. (2) Enter a generation number and phase into the generation fields; click "Convert to year", and the year appears in the year field with AD or BC selected as appropriate; click "Convert to BP" and the BP figure appears in the year field with BP selected. (3) To convert BC to BP etc., first convert to generations by (1) then convert back to AD/BC or BP by (2).)

(No program? See only a red X? You need to install the Java Runtime Environment (JRE). Click here.)

(Please ignore. This is for my reference only: original archive location = "http://marc.widdowson.googlepages.com/Generation.jar")

While I propose to start using generational dating in future posts, I will include in brackets the more conventional date in either BC/AD or BP format. This provides a compromise between consistency and intelligibility.

Finally, I note three other aspects of the generational dating scheme:

If somebody was born in G n, then their parents were almost certainly born in G n-1, while their grandparents were almost certainly born in G n-2.
If someone was born in G n, and did not die prematurely, they were probably still alive in G n+3 but dead by G n+4.
The life of a person born in G n will typically just about overlap the lives of people born between G n-3 and G n+3.
Each generation reacts against its predecessor, so that people tend to have more in common with their grandparents than with their parents. This implies a two-generation oscillation in social attitudes, which should show up in the generational scheme as a difference between odd-numbered and even-numbered generations. The pattern will not be exact since our standardised generation length of 25 years is not necessarily equal to the 'true' generation length. However, it might hold roughly over short periods of one or two centuries. This roughly 50-year (2 g) oscillation might be the same as the roughly 60-year Kondratiev wave.

Scale and competition

2009-08-09T15:49:00.055Z

In The Dynamic Society, Graeme Snooks stresses the importance of the demand for as opposed to the supply of ideas in driving technological change. In other words, necessity is the mother of invention.

A society's technology is wrapped up with its other characteristics in an eigenmode. An invention like writing should be seen not as a lucky discovery but as an inevitable concomitant of a particular level of social development. Inventing writing is not really that hard. It comes into existence in a high-scale society because such a society cannot function without some means of recording information. It is not fruitful to ask whether writing causes or is caused by a given scale. They go hand in hand, that is all it is meaningful to say.

To extend the point to a recent, familiar example, the internet is associated with an increase in the scale of global society (we can get in touch with more people, more easily). The conventional view would be that some boffins invented the internet, and scale increased as a result. However, it could equally be argued that the development of the internet was driven by the needs of governments and businesses struggling to deal with increases in social scale. We have all heard of inventions like Leonardo's helicopter that languish in limbo because they are 'ahead of their time', showing that merely coming up with an idea is not enough. With the internet, people only invested in it because it filled a real technological gap. Again, the eigenmode concept says we do not need to choose between these opposing viewpoints, i.e. as to whether the internet led to increased scale or increased scale led to the internet. The internet and increased scale both caused each other, while the precise steps by which this came about would not tell us much even if we knew what they were.

I say all this because Snooks's observations have made me think again about geographical influences on technological development, and how I may have been insufficiently rigorous when discussing this in an earlier post.

Thus, I previously put up the following diagram, as part of an explanation of why development first took off in the more centrally located regions of the world's landmasses.

The argument was that more centrally located regions had higher scale, i.e. higher social interactivity, because there were more people within shorter range than was the case for societies around the periphery, and this higher scale meant a higher level of technological development. (I went on to explain that as technology, especially sea-going technology, evolved, it changed which societies counted as central and thus changed which regions had the highest scale and were the most advanced.)

While I continue to stand by this argument, I may have been misleading in implying that it was the flow of ideas from neighbouring societies that was the critical factor stimulating the development of the centre.

What I now want to emphasise is that all we can really say here is that high scale (i.e. proximity of large populations, due to the central location) meant there was societal development and complexification. The details of how this happened are not critical. It may be that centrally located societies were stimulated by the strong flux of ideas reaching them from all the surrounding societies. However, Snooks would argue that the important thing was the pressure exerted on the central societies by their neighbours. In his view, the central societies, with so many close rivals, had to struggle harder to survive compared to the more isolated, peripheral societies, and it was this intense competition that stimulated or compelled them to develop. As before, it is fruitless to get into a debate about which of these viewpoints is correct. Probably both aspects played a part, and there may be other factors or mechanisms as well.

It is not my intention to provide a full review of Snooks's book, which is one of a series in which he sets out laws of history. However, it is worth saying that I do not agree with his assertion that the demand for ideas was the only issue, while for the most part I found his book pretty confused and simplistic.

Snooks presents his theory as describing biological as well as sociological evolution. This, to me, is a red herring. (It is, however, surprisingly common. Kenneth Boulding does this in Ecodynamics, as does Stuart Kauffman in At Home in the Universe and also arguably Richard Dawkins with his concept of gene-like social memes). Yes, there are superficial analogies between biological and sociological phenomena - e.g. the Roman empire was born, lived and died - but they disappear on close examination - e.g. the Roman empire did not actually 'die', nor was it really 'born'. Biology and sociology exist on quite different levels and need their own conceptual tools. On the sociological side, which is what I am concerned with, we need to use the ideas of politics, economics and cultural anthropology, not the ideas that make sense in biology.

Snooks argues that the lack of development of the Australian aborigines was because their isolation meant they were not exposed to significant competitive pressure. (Felipe Fernández-Armesto takes a similar view in Pathfinders [p. 11], where he describes the aborigines as "the 'dropouts' of 50,000 years ago, opting out of worlds of change in order to settle a new continent, where they could maintain a traditional way of life".) However, one could ask why the aboriginal tribes did not compete with each other; it might be thought that being cooped up in a small continent could even have increased competitive pressure. Elsewhere, Snooks introduces the notion of 'funnels of transformation', which are narrow regions like Mesoamerica and the Middle East, where many peoples passed through, creating pressure for development. Australia, apparently, had no such funnel. There is something in this, but why do certain geographical conformations have this funnelling effect? Snooks does not really address this. However, it emerges naturally from the 'scale' concept and the idea that sophisticated social mechanisms are needed to deal with intense interaction among close-packed populations connected by short lines of communication.

Snooks refers repeatedly to 'The Industrial Revolution', which seems to play a large role in his thinking. I find this especially surprising when he himself points out, for example, that sixteenth century growth rates, i.e. two centuries before the 'industrial revolution', exceeded those of any other period bar the 1950s and 1960s. (And he notes high growth rates at other times as well.) The 'industrial revolution', in the sense of a special period in history when technological change suddenly became dramatic, is an illusion. Industrial development during this part of the eighteenth and nineteenth centuries grew seamlessly out of what had gone before, and it was then just the latest twist in the ongoing acceleration of technological evolution. The term 'industrial revolution' originally arose as a pun, jokingly implying that, while France and other countries had political revolutions between about 1750 and 1850, Britain had an industrial revolution. The concept then stuck. It seems that people have a weakness for such explanations of history that assign special significance to particular periods and 'turning points'.

Despite my above criticisms, I would still recommend reading Snooks's books. His work has made me more aware of the issue of demand-side versus supply-side explanations of the evolution of ideas, and indeed of the fact I may have lazily slipped into naive, supply-side explanations myself. He also makes other worthwhile points, such as that co-operation and competition are both necessary in an economy. However, I have reservations concerning his overall model. It is not that it is necessarily 'wrong' in a straightforward sense, but I think it is too vague and impressionistic to be any real use as a theory of history.

World languages

2009-07-27T14:03:00.079Z

The distribution of languages conveys information about ancient migrations and cultural encounters. To historians this is arguably more useful than the information provided by gene distributions, even though those are currently highly fashionable. Whereas genetics preserves a biological record of human movements, language preserves a sociological record.

For example, genetics seems to show that most modern Britons have ancestral roots in Britain going back to the Mesolithic period. This challenges the traditional belief that waves of Anglo-Saxon, Viking and Norman invaders arrived in more recent times. It suggests these invaders did not displace the existing population, and were in fact relatively few in number.

Yet this does not mean the Anglo-Saxon, Viking or Norman settlements were trivial and irrelevant, as some interpreters of the genetics research tend to imply. They were each historically important in shaping British society and culture, and their effects continue to reverberate down to the present.

Bede tells us of the struggles of the English (Anglo-Saxons) with the British, both on the battlefield and in the domain of religion, the result of which was that the Celtic Christianity of the indigenous 'British' was replaced by the Roman Catholicism of the newly converted 'English'. Many of those defining themselves as English may in fact have had British blood or British genes (perhaps having found it paid to be English since they were the ones winning the battles), but that makes little real difference to the process of cultural change, which is what matters for history. One legacy of the process Bede describes is the separate national consciousness of Welsh and English in modern Britain, and that has very real consequences, whatever the DNA might say. It has been argued this separate consciousness pre-existed the Anglo-Saxon invasion and that may be the case. Nevertheless, it is the Anglo-Saxon invasion that is used today to justify and explain the situation, so in that respect it remains historically pertinent.

The Vikings long raided Britain, causing disruption and defensive responses among communities on the coasts and major rivers, and they went on to establish more permanent jurisdiction, known as the Danelaw, over an area of eastern Britain. People in the rest of the country were forced to pay a special tax, the Danegeld, to keep the Vikings at bay. Although the consequences of the Viking occupation are not so obvious today, it dominated several centuries of British history, affecting settlement patterns, taxation, law and commerce on both sides of the divide. There may or may not be much Viking DNA in the modern British population, but British history is steeped in their presence.

The Norman conquest of 1066 dispossessed many of England's existing lords and landowners, and substituted a new French-leaning nobility. This ensured that for the next few centuries English kings would often be at war in France, defending their French territories. It also provided a conduit for the infusion of continental fashions into English society. The Normans' genetic contribution may have been minimal, given that they were a tiny elite, and indeed many of the great families that later claimed to have 'come over with William the Conqueror' probably had mainly Anglo-Saxon forebears. Nevertheless, their cultural contribution was profound, and 1066 is now usually seen as the beginning of English history, with everything beforehand a kind of prologue.

The point is that these invasions, though perhaps scarcely visible in British genes, all left their mark on Britain's language.

The fact that (most) British people speak English is thanks to the Anglo-Saxons, whose language it is.
The Vikings contributed a few words to the English language and a greater number to various dialects - the north-eastern dialect word 'ta' (for 'thank you') comes from the Scandinavian 'tak' - and the area of the former Danelaw is characterised by numerous place names ending in -by and -thorpe.
The Normans introduced many French words, giving English a particularly rich vocabulary, often with both Germanic and Romance words as alternatives for the same concept. Modern English even contains vestiges of the social difference between the French-speaking elite and their Anglo-Saxon subjects. The words for farm animals, which were tended by the peasants, are Anglo-Saxon (e.g. pig, cow), while the words for meat, which was eaten by the lords, are French (e.g. pork/porc, beef/boeuf). In general, Anglo-Saxon words tend to be more earthy and vulgar.

Anyone living in Britain and participating in British society, regardless of their genes (including any genes for skin colour), is an inheritor of the cultural legacy of 1066 and all the other events and processes that have made Britain what it is today. The attitudes and practices that people share by virtue of belonging to the British population are transmitted by social learning, not handed down in a person's DNA. Someone who looks and acts completely British could be descended from very recent immigrants, while a 'British' baby brought up in France would become culturally French. Language is a more meaningful indicator of the historical background of a given society than the genetic make-up of its individual members.

Furthermore, English is now spoken in many places outside Britain in a pattern that reflects the events of world history. It is the main language of North America, Australia and New Zealand because those are places that once belonged to the British Empire and where the indigenous population was overwhelmed by European settlers. It is also an important language in India and some African countries because they too belonged to the British Empire, though the native society survived British rule. English continues to spread around the world thanks to the influence of the United States and its cultural exports. Meanwhile some words have entered English from the languages of Britain's former colonies (see here for a list of loanwords, and here for discussion), again providing a linguistic record of historical contacts.

Nor is it just English, of course. The fact that a form of Dutch (Afrikaans) is spoken in South Africa or that French is spoken in Quebec similarly records past migrations.

Languages, meanwhile, change over time. When a language is carried into a new region, it may drift apart from its parent. American and British English have developed differences of grammar and vocabulary. French, Spanish and Italian all evolved from Latin, reflecting the fact the relevant countries were once part of the Roman Empire, but their evolution followed different paths.

This means that the imprint of history is to be found not just in the distribution of a particular language but in the distribution of a family of related languages that may have evolved from some parent language.

Furthermore, families of closely related languages can be grouped into larger families of more distantly related languages descending from a grandparent or great-grandparent language.

Some linguists have taken this grouping process to the limit, classifying all the world's languages into a small number of enormous groups. Their work remains controversial, as people dispute not only the assignment of languages to groups (e.g. Basque to Dene-Caucasian) but even the very existence of top-level language families.

The following figure shows the distribution of these proposed language groups (for the key, see below). It is based on C. Goucher and L. Walton, World History: Journeys from Past to Present, p. 6. As just explained, similarities of language reflect past (or ongoing) migrations and/or cultural contacts. Hence the distribution of language groups is also the distribution of historically connected societies. Note that the map does not reflect recent European migrations, i.e. it considers only the native American and aboriginal Australian languages--not the English, Spanish or Portuguese that in fact now dominate in those regions.

(To open the map in a full Google Maps page, click here. For a Google Earth equivalent, click here.)

View Larger Map

Here is the key to the language families:

Glottochronology allows linguists not only to determine that languages are related but also to determine when they split from a common ancestor. It relies on assumptions about the rates of change in languages' sounds, vocabulary and grammar. Again, both the technique and its findings remain controversial.

To the extent that glottochronology can be trusted, it means we can go beyond the simple conclusion that societies are historically connected, and deduce when the relevant contacts or migrations occurred.

Language is therefore a vital resource for those wishing to study how societies became what and where they are now. For those who want to pursue such a study of what language can tell us about the past, the Tower of Babel website is a good starting point, with detailed maps and databases of the world's languages.

Without embarking on a detailed study, what can we learn from the broad-brush map of top-level language groups shown above?

First, note that the most linguistically diverse areas are in the tropics: Africa, Central America and South-East Asia respectively. This point is reinforced by the map below, which shows the geographic centres of the world's languages. It can be seen that language is most diverse in the equatorial regions of Africa, America and the Far East. (The most linguistically diverse area on the planet is the island of New Guinea.)

This linguistic diversity of Africa, Central America and South-East Asia tells us that these are regions where societies have been settled in a relatively stable configuration for a long time, rubbing up against each other but never seeing any society completely overcome the others.

Thus, while it is a natural assumption that languages drift apart when the populations speaking them are isolated from each other, language in fact changes most rapidly among populations that are in contact but that perceive themselves as separate. Language differences are used to emphasise contrasting senses of identity. This was shown by Labov's work on how the inhabitants of a tourist resort changed their accent in order to differentiate themselves from the incoming holidaymakers. The original paper is: William Labov, 'The social motivation of a sound change', Word 19 (1963), pp. 273-309.

What is true of language is true of culture in general. With the emergence of modern humans during the upper palaeolithic, there was a quickening rate of local cultural divergence, and this can be linked to population pressure. As humans filled up the world, rival groups were increasingly forced into contact, and responded by creating distinctions between themselves through linguistic and stylistic markers.

The antiquity of societies in the intertropical belt can be linked to the changing climate of the Holocene. During the Last Glacial Maximum (LGM), northern and southern latitudes became at best inhospitable, at worst inaccessible, through being covered with enormous ice sheets. Societies in the inter-tropical zone have been adjusting to each other since the start of the upper palaeolithic some fifty thousand years ago. Societies outside this zone are the result of more recent expansions and have had less time to adjust and reach stasis.

With the emergence of truly modern human societies at the start of the upper palaeolithic, humans spread rapidly all over the world, including to Australia and the Americas.

Once the world was full, societies became tied to particular regions and developed separate identities. They evolved cultural and linguistic markers to differentiate themselves from their neighbours.

As world climate cooled at the onset of the LGM, societies from northern and southern regions were forced back towards the tropics while retaining their separate sense of identity and concomitant linguistic markers. There emerged a situation in which numerous societies speaking multiple languages were concentrated in a relatively small space. This is the reason for the diversity of top-level language groups in the equatorial band.

As climate warmed again and the ice sheets retreated, humans spread back away from the tropics. This was largely a single language group, the one on the periphery, best poised to move into the newly emerging lands. Those within Africa or South-East Asia were blocked by their neighbours from expanding north.

In each region, societies continued to segment and differentiate themselves, so that languages continued to diversify. This process has proceeded furthest in the tropical zone, where societies have been packed together the longest.

Note that a similar argument can be constructed about genetic diversity. This suggests that the geneticists' current assumption, that humans spread out in one direction from a common source region, with diversity diminishing the further you get from the source, are overly simplistic. They need to take into account rebound effects, whether due to the LGM or for other reasons. This will make the analysis messier and more complicated, and should challenge some of their conclusions, e.g. about timings of migrations.

Another point to note from the distribution of top-level language groups is the presence of three such groups in the Americas.

The main group, Amerind, is only found in the Americas. It encompasses societies descended from the first settlers in the Americas, who came as part of the original expansion pulse of modern humans, fifty thousand years ago. We do not know how these people arrived. They probably came across the Bering land-bridge that in those times connected north-east Asia to north-west America. However, they may have come across the Atlantic or Pacific oceans, or some combination of these routes.

The second group, Dene-Caucasian, is found in both northern North America and east Asia. This represents a wave of settlers coming across the Bering land-bridge as part of the re-expansion into northern latitudes during early stages of warming after the LGM.

The third group, Eurasiatic, is the same as that spread across most of Asia and Europe. It represents societies that expanded more recently, during the Holocene proper, overwhelming earlier Dene-Caucasian settlers with higher technology. This expansion, no doubt like earlier ones, has had several major and minor phases. On the most recent, major phase, see The Horse, The Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World by David W. Anthony. These societies also penetrated into North America, travelling by boat across the top of the North Pacific. By this time their culture was adapted to northern living.

A third observation concerns the existence of vestiges of earlier settlers that held out against the Eurasiatic expansion just referred to. These comrpise Dene-Caucasian speakers in the Basque country of highland Spain, in the Caucasus, and in central Siberia, and Kartvelian speakers, again in the Caucasus. Other vestiges survived for varying periods but have by now given up their separate identities.

A final point is the adventurousness of the Austric-speaking societies of maritime south-east Asia. People from these societies settled the far-flung islands of the Pacific.

Maritime south-east Asia seems to have been the locus of early maritime technology, stimulated no doubt by the environment of the Indonesian archipelago, which presented sea journeys that were challenging but not too challenging.

The last great colonisations by these people were those of Hawaii, Easter Island, New Zealand and Madagascar, between 1000 and 2000 years ago.

In Madagascar, they encountered earlier settlers who had arrived from the African mainland during the original human expansion. The far-flung Pacific islands, however, had not been reached in the original human expansion, and Austric-speakers were the first to settle them.

Once the whole Pacific had been colonised, sea-going activity declined, and only short-distance journeys continued to be made. This demonstrates the point that humans expand very rapidly into empty lands, but settle down and lose their mobility when they have become surrounded by neighbours.

Understanding early human migrations

2009-05-22T19:00:00.062Z

I wish to explain why I do not worry that my beliefs concerning the initial colonisation of the world--i.e. that it occurred in a sudden pulse 40-50,000 years ago--are at variance with current mainstream thinking on this subject. In a nutshell, it is because mainstream thinking is undoubtedly immature and will be revised extensively as time goes on.

In the 1970s, archaeologists thought they had a good idea of how the world was settled, and, in particular, their understanding seemed to supersede the older idea that humans had spread out from a single source during the upper palaeolithic.

[Today] many authorities believe that...leptolithic [upper palaeolithic] man (of the modern species, Homo sapiens sapiens) was the direct descendant of the Neandertalers. Such a view contrasts strongly with the earlier opinion that the leptolithic cultures were brought to Europe by an immigration from the Near East of H. sapiens, who wiped out the earlier and 'inferior' Neandertal population.
David and Ruth Whitehouse, Archaeological atlas of the world, 1975, p. 39.

This view has itself now been superseded, and the latest genetics research is taking us back to the original idea, that humans originated in one place and, from there, colonised the rest of the planet.

Clear genetic trees for both modern Y chromosomes and mtDNA point back to a recent common ancestor of all modern humans within the last 200,000 years and a migration out of Africa less than 100,000 years ago. This new line rather quickly replaced all pre-existing human genetic lines, including the Neanderthals...[T]here is no convincing evidence for [interbreeding] in our male and female gene lines.
Stephen Oppenheimer, Out of Eden: The peopling of the world, 2004, p. 347.

It would be premature to assume that we now have perfect knowledge and that the latest ideas will not be superseded in their turn. Genetics is a new tool, and in the rush to apply it there has been little attention paid to its limitations, which will gradually come to light. The development of understanding is a process of successive refinement. It will not be complete until history itself comes to an end.

A major reason why ideas about early human migrations (or any other aspect of the past) keep changing is that they focus on material evidence and often on only one kind of such evidence (pots, genes). Material remains can never provide a full record of the living, breathing past, and will always leave ambiguities. To round them out, it is necessary to take account of everything we know, from contemporary and historical experience, about how societies function. Although some archaeologists do study modern farmers and hunter-gatherers in order to understand those of the past, what I am really referring to is the kind of total historical theory based on abstract theoretical principles to which this website is devoted. Such a theory, treating all human experience as one, will allow us to build a more reliable understanding than comes from concentrating on pots, genes or whatever kind of evidence might come along in future.

Humans have always wondered how they got to be where they are now. Many peoples have foundation myths in which their ancestors arrived from somewhere else. The Aztecs recalled their origins on the North American plains. Many Andean societies believed they had emerged from underground. Some Maori tribes celebrate the ancestor Kupe who first came to New Zealand. The English, and to a lesser extent some continental European nations, link themselves to barbarian invaders who plundered the collapsing Roman Empire.

These traditional stories are often fantastical in their details, and they leave such questions as whether an invading group replaced the original population or merely superimposed the thin layer of a conquering elite.

In the early twentieth century, archaeology appeared to be shining the light of science on the problem. The distinctive styles of ancient artefacts (e.g. shape/decoration of pots and tools) seemed to demarcate distinctive cultures associated with different human groups. When artefacts of a particular style were found to spread from one area to another, this was assumed to reflect a displacement or expansion of the people of the corresponding culture.

By the later twentieth century, theorists began to doubt the formerly confident conclusions they had arrived at in this way. It was recognised that the diffusion of cultural objects did not necessarily require the movement of people. Artefacts might travel along trading networks, or one group's styles might simply be adopted by its neighbours. Archaeologists went almost to the opposite extreme, denying the possibility of population movement at all.

Today the evidence and its implications remain uncertain. The main conclusion is the sheer complexity of the interactions and travels of prehistoric peoples.

The Beaker Folk were once deemed to be recognisable by their pottery (see picture, right) and related artefacts, and the spread of Beaker objects in the third millennium BC was thought to represent a wave of technologically advanced people colonising much of north-western Europe. Later, it was thought to represent just the transmission of the technology and an associated belief system. The modern thinking is that both aspects played some part, though any migration was tentative and targeted, not the sweeping motion once envisaged.
The Anglo-Saxons were long thought to have invaded Britain after the collapse of the Roman Empire, bringing a new language, religion and way of life, and driving the original Britons west into Wales and Cornwall. This is the story we have from Bede, who lived within a couple of hundred years of the events. It seemed to be confirmed by the appearance of new kinds of artefacts in the archaeological record, around the relevant time. However, the archaeological evidence has come to look problematic, with close intermingling of the supposed 'British' and 'Anglo-Saxon' material, and some of the changes taking place apparently before the time of the alleged invasion. In the last decade or so, it has been increasingly argued (by both professional and amateur theorists) that there never were any Anglo-Saxon invasions, and the distinction between eastern 'English' and western 'British' has existed in Britain from Mesolithic times. This is despite explicit references to an invasion in contemporary sources (e.g. the Gallic Chronicle of 452, under the year 408). Most historians and archaeologists would today be cautious about making firm statements in any direction.

While the archaeology has looked increasingly debatable, it is now genetics that seems to have all the answers, and again it seems to be based on clear-cut scientific reasoning.

The genetics approach makes use of haplotypes, i.e. specific markers in mitochondrial and Y-chromosome DNA, which are inherited in only the female and male lines respectively, and which embody a precise record of a person's ancestry. For a clear description, see this charts and diagrams website. The technique was also discussed in an earlier post, where I mentioned my suspicion that the flaws in its assumptions will be revealed in due course.

The Genographic Project, a National Geographic website, presents an Atlas of the Human Journey, based on the new genetic findings, and allows you to get your own DNA tested and your origins worked out.

Before the use of haplotypes came along, human genes had already been studied for a long time by another method. This is population genetics, which considers the genes on ordinary chromosomes that can be passed down by either the male or female line. Unlike the haplotype technique, population genetics offers few easy answers and creates a complicated picture.

Population geneticists are sceptical of the new arguments of the haplotype researchers. At a 2005 symposium, geneticists working on haplotypes were invited to analyse an artificial dataset whose 'ground truth' was known. While it was agreed the precise results would not be revealed, it has been admitted they were less than spectacularly successful (see Simulations, genetics and human prehistory, ed. S. Matsumura et al., p. 192).

Another indication that haplotype data may be more ambiguous than its practitioners care to acknowledge is the fact that commercial companies offering ancestral DNA testing have been found to give inconsistent results. The biochemical reactions extracting the DNA profile are presumably precise and repeatable, but the significance of the results is more a matter for opinion and interpretation.

None of this is to say the new genetic methods, or indeed traditional archaeology, are useless for understanding early human migrations. The point is simply that we should take the latest pronouncements on this subject with a pinch of salt. We are still in the early stages of unravelling this aspect of our past.

Climate and history

2008-07-04T16:30:00.112Z

While history should be explained in terms of society's internal dynamic and never purely in terms of external factors, the environment does impose constraints on what can happen. People cannot live on ice sheets, for example, and difficult terrain, such as forest or desert, means low scale and low development.

To understand how people colonised the planet, we therefore need to take account of the environmental context, i.e. the changes in climate, sea level and ice cover over the last 40,000 years.

The methods for reconstructing ancient climates are described by a number of books. The one I used was Global Environments Through the Quaternary by David Anderson, Andrew Goudie and Adrian Parker. The book's Amazon page links to some other titles covering the same area. Another one worth mentioning is Earth's Climate: Past and Future by William F Ruddiman.

The Quaternary Ice Age

Viewed on geological timescales, the 40 thousand years of the human story have occurred during an unusually cold phase of our planet's history. This is the Quaternary Period, which began some 2 million years ago and is regarded by geologists as an ice age.

Geological time is divided into various periods, which can be recognised by differences in the type of rock laid down (e.g. rocks from different periods contain different kinds of fossil). These periods are often named for the regions where the associated rocks were first noticed (e.g. the Jurassic takes its name from the Jura), although some get their names in other ways (e.g. the Cretaceous takes its name from the Latin for chalk, since that is what the rocks consist of).

The Quaternary is the most recent period. Its name comes from a former scheme that divided earth history into Primary, Secondary, Tertiary and Quaternary periods. Of these, only the Tertiary and Quaternary are still recognised (though even this terminology is now coming into question). Conventionally, the Quaternary began 1.8 million years ago, but many geologists now put this back to 2.6 million years. The controversy is irrelevant to us, since we are only interested in the last 40 thousand years - roughly the last 2 percent of the Quaternary - the time for which modern humans have been in existence.

What distinguishes the Quaternary is that during this period the earth has been in its 'ice house' mode, whereby there are ice caps at the north and south poles. It is not usual for the earth to have such ice caps. There were none during the great age of the dinosaurs, 100 million years ago, for example. However, from time to time, the earth's climate goes through a noticeably cooler phase. No one knows why this occurs, even though there are many theories. Whatever the reason, over the last 3 billion years, there have been some half dozen such glacial episodes, each lasting up to 100 million years. In the Quaternary, we are currently in the early stages (if past durations are anything to go by) of the latest of these ice ages.

The current cooling of the earth's climate began as long as 65 million years ago, at the end of the Cretaceous (when the dinosaurs died out). The cooling trend continued throughout the Tertiary, the period immediately before our own. In fact, ice sheets were already appearing in the late Tertiary. It is when these became persistent, and temperatures reached their current low, that is taken to mark the start of the Quaternary.

Climate chaos

While the Quaternary as a whole has been cold, temperatures have by no means remained constant during this time. In fact, not only have temperatures fluctuated but there have been smaller fluctuations within larger fluctuations. The more evidence climatologists gather, and the closer they look, the more ups and downs become apparent. Within the Quaternary, there have been warmer and colder millennia; within a given millennium, there have been warmer and colder centuries; within a given century, there have been warmer and colder decades; within a given decade, there have been warmer and colder years. Climate fluctuates on all scales.

The fact that climate fluctuates on all scales suggests it is a chaotic system. External inputs--such as variations in solar activity, continental drift, the passage of the solar system through interplanetary clouds, or gases released by volcanoes and living organisms--energise the system. They do not directly drive change, except possibly large, long-term change, but rather prevent the atmosphere from reaching equilibrium. The system remains unstable in itself, and is bound to change in an essentially patternless, unpredictable manner, on account of complex, multi-level feedbacks between climatic variables.

One of the earliest pieces of work in chaos theory was, in fact, the research of Edward Lorenz on computer models of the atmosphere. He found his simulated weather systems wandered all over the place in a way that had no simple relationship to the input conditions. Given that the weather seemed to vary continuously and unpredictably, he questioned whether it even makes sense to speak of the earth's 'normal' climate.

The diagram below shows some of the differing climatic regimes of the Quaternary, which will be explained in the following sections. Red represents warmer phases, and blue colder ones.

Glacials and interglacials

The grossest temperature fluctuations within the Quaternary are the glacials (or glaciations), when ice sheets grew massively around the world, and interglacials, when the ice sheets retreated and in some cases disappeared.

The most recent glacial is known as the Würm glacial in Alpine Europe or as the Wisconsin in North America (and has other names in other regions). This began around 75,000 years ago, was at a point of maximum coldness around 20,000 years ago (the Last Glacial Maximum or LGM), and came to an end around 11,500 years ago. We are currently in an interglacial.

Pleistocene and Holocene

The relatively warm period that began 11,500 years ago is considered to be a distinct sub-division (or epoch) of the Quaternary, called the Holocene. All the rest of the Quaternary, before this, is called the Pleistocence. Pleistocene means 'very recent'. Holocene means 'completely recent'.

Some geologists dispute the notion of the Holocene as a special epoch. They have a point, as it is only the last of a series of interglacials. The idea that it marks a new epoch seems to be exaggerating the importance of a relatively minor change simply because of our closeness to the event. That said, the Holocene provides a useful label for the current warm phase, whatever its geological status.

Marine isotope stages

The broad pattern of glacials and interglacials was first identified in the nineteenth century by the characteristic valleys and deposits of debris left by ancient glaciers. However, a much more detailed record of our planet's changing ice cover is now available from studies of ocean sediments.

Seawater molecules (H₂O) contain two isotopes of oxygen, ¹⁶O, the lighter of the two, and ¹⁸O, the heavier. When water is evaporated from the oceans, to fall as rain or snow over the continents, the lighter water molecules, containing ¹⁶O, evaporate a little more easily. If the earth is going through a cold spell, and ice sheets are growing, these lighter water molecules become locked up in the ice, leaving the oceans with a higher concentration of the heavier molecules. Later, when the earth warms and the ice sheets melt, the lighter water molecules return to the oceans, reducing the concentration of heavier molecules there. This means that the concentration of ¹⁸O in seawater reflects the size of the earth's ice sheets, with higher concentrations of ¹⁸O when the ice volume is larger.

We can reconstruct past variation in ¹⁸O concentrations because the shells of tiny animals that live in the oceans reflect the chemical composition of the water that surrounds them. If ¹⁸O is more concentrated, these shells also contain a higher concentration of ¹⁸O. When the animals die, their shells fall to the bottom of the oceans and build up as layers of sediment, creating a record of the changing concentration of ¹⁸O and hence of the changing size of the earth's ice sheets.

Although this 'marine isotope' record shows fluctuations of all sizes and durations, geologists recognise in it an overarching pattern of swings between warmer (less ice) and colder (more ice) stages. The current warm swing is designated marine isotope stage (MIS) 1. The previous cold swing is MIS 2. The warm swing before that is MIS 3, and so on. Odd numbers correspond to warmer stages and even numbers to colder stages.

The marine isotope record does not tie up exactly with the more traditional division into glacials and interglacials, but rather reveals the complexity of climatic fluctuations. The current warming (MIS 1) had its beginnings in the last few millennia of the Würm glacial. The previous cold phase (MIS 2) was an exceptionally cold part of the Würm glacial, spanning the LGM. Before that, MIS 3 was a less cold phase, but still within the Würm glacial and not as warm as today.

The ending of the last glacial

The overlap between the nominal end of the last glacial and the beginning of MIS 1 reflects the fact that the colder climate did not terminate in a once-and-for-all manner. Within the warming, there were setbacks, involving a temporary return to colder conditions. First there was a warming lasting a little under 2000 years (the Bølling), then a short cold snap of about 3 centuries (the Older Dryas), then another warming of a little under 1000 years (the Allerød), then a longer cold snap of nearly 1500 years (the Younger Dryas). The end of the Younger Dryas marks the end of the glacial.

It should be apparent from all this that identifying the termination of the glacial is somewhat arbitrary, and requires a degree of hindsight we do not currently possess. Whether the present warming should be seen as part of a longer-term warm phase or just as a warmer interval in a longer-term cold phase depends on what happens in the future.

Climatic variation in the Holocene

During the Holocene, climates have continued to fluctuate. In Europe, the first 1500 years (the PreBoreal) were relatively cool. There then followed 7500 years of relative warmth, ending 2500 years ago (i.e. around 500 BC). The beginning and end of this phase (the Boreal and SubBoreal) were both warm and dry, while the middle part (the Atlantic), lasting about 3000 years, was warm and wet. Finally, the last 2500 years (the SubAtlantic) have been relatively cool again.

Chronozone	Climate	Chronology
SubAtlantic	generally deteriorating climate with cooler and wetter conditions	600 BC to present
SubBoreal	climatic optimum with warmer and drier conditions	3800 BC to 600 BC
Atlantic	climatic optimum with warmer and wetter conditions	6900 BC to 3800 BC
Boreal	climatic amelioration, warmer and drier	8100 BC to 6900 BC
PreBoreal	subarctic conditions	9600 BC to 8100 BC

Adapted from: D Anderson et al. Global environments through the Quaternary (Oxford 2007) p. 11.

Again, within the current (SubAtlantic) phase, there have been shorter term fluctuations. The heyday of the Roman Empire was relatively warm. The end of the Empire and the early medieval period (the 'Dark Ages') was colder. The high middle ages, the time of the monasteries and crusades, was warm, with grapes being grown in Britain, and the Vikings settling Greenland. The early modern period, the time of Shakespeare, Elizabeth I and Philip II, up to the Victorian period was colder (the 'Little Ice Age').

The last hundred years or so have been relatively warm, but still by no means uniformly so. The first half of the twentieth century was warm, and scientists spoke of global warming as a boon to humanity, bringing not just better weather but better growing conditions for crops. The late 1940s to 1970s were cooler, leading to talk of a renewed ice age, with soaring energy costs for heating, and the threat of famine; in the 1970s, British harvests were on average 11 days later than they had been in the mid-twentieth century. The 1980s and especially the 1990s were warm again, so that talk was once more of global warming, though now as a source of concern and even fear. Finally, temperatures in the first decade of the twenty-first century have shown little trend either way.

To repeat, climatic fluctuations occur on all scales, and the closer one looks, the more variation one sees. This is variation not just in time but also in space. Episodes like the medieval warm period and subsequent little ice age do not appear to have occurred in other regions the same way they occurred in Europe, and temperature changes in the southern hemisphere seem sometimes to have been in the opposite direction to those in the northern hemisphere.

Sea level changes

Changes in global ice cover cause corresponding changes in the global sea level. More ice means less water in the oceans and larger areas of dry land.

This would have affected people's ability to get from A to B, and is important for how they migrated around the world.

The chart at right (source: Wikipedia) shows changes in sea level through the late Quaternary. The light and dark shaded bands indicate the marine isotope stages (note that MIS 5 is subdivided into 5a, 5b etc.).

For most of human existence, sea level has been lower than today, reaching a minimum at the LGM, when it was more than 100 metres below the present level. Around 5000 years ago, however, sea level was some 10 metres higher than it is today.

We can translate the above chart into maps of how the continents would have looked at different times, courtesy of an applet developed by Sebastien Merkel at the University of Lille. You enter a given sea level (metres above or below the present) and the applet draws the land as it would then appear. (There are actually several applets, for the world as a whole and for different regions.)

I have used Sebastien's applet to create a slideshow of changing sea level, spaced at 5000-year intervals, from 40,000 years ago to the present.

Here is a Youtube version:

I have also created a set of Google Earth layers showing the ancient coastlines. (This does not include a layer for the present, since you can get that from Google Earth itself.)

Below, is an animated version, which requires the Google Earth plug-in to see it. Move the slider to change the date. (If you do not want to install the plug-in, but have a standalone Google Earth browser, you can download the animated coastlines here.)

Lower sea levels meant that the world's land surface was more connected in the past than it is today. The British Isles were joined to continental Europe. There was a land bridge, known as Beringia, between Asia and North America. The islands of modern Indonesia were mostly joined to each other and to the mainland. Australia was the only separate continent, cut off by a sea crossing of about 100 miles, but was joined to New Guinea. The entrance to the Black Sea was dry land, so the Black Sea was then a lake. However, the Gibraltar Strait remained submerged, so there was a short sea crossing between Africa and Spain, while the Mediterranean still opened into the Atlantic Ocean.

Early human migrants would have followed the coasts in spreading around the continents, and followed the rivers into the interior. The early settlement of Australia shows they could also cross the sea. Evidently, they had boats, which would have served them for both fishing and transport. They could thus have crossed between Africa and Spain, and reached offshore islands, such as those of the Mediterranean, Caribbean and South China Sea.

The rise in sea levels means that most of the sites occupied by human migrants 40-50,000 years ago are now beneath the waves. Future advances in underwater archaeology can be expected to reveal much more about this time, and give a clearer picture of the colonisation of our planet.

Climate maps

The pattern of coastlines and land connections represents only part of the information we need for thinking about how early humans moved around the planet. We also need to know the type of terrain that confronted them.

For example, while the low sea levels of the LGM produced the Beringia land bridge between Asia and North America, the heavy glaciation of that time meant that Beringia was blocked from the rest of the North American continent by an ice sheet. Given the traditional belief that humans only reached the Americas after the LGM, the moment at which the ice sheet had retreated enough to leave an ice-free corridor from Alaska to the Great Plains provides an important constraint on the timing of their arrival. (For an animation of the retreat of the North American ice sheet, see this site.)

My view is that the earth, including America, was colonised in essentially one great movement, at the start of the Upper Paleolithic, i.e. 20-30,000 years before the LGM. Beringia existed at that time, while the North American ice sheet extended only a little way beyond Hudson's Bay, and did not block movement via the west coast. That said, we should not discount the possibility that humans arrived in America via the Atlantic or Pacific. It may be a long voyage, but the Americas present a huge target.

I have prepared a set of maps, in Google Earth, of global climate/environment at 10,000 year intervals, from 40,000 years ago to the present. They are derived from those produced by the Quaternary Environments Network plus a certain amount of guesswork (the QEN maps are quite patchy in their chronological and regional coverage, and I have had to fill in the gaps to create a consistent set of maps at regular intervals).

Terrain is classified into eight types, using the following colour scheme. In a nutshell, the lighter the green, the drier and more open the terrain (plus yellow for desert, including polar desert, and white for ice).

You can see these maps either with the Google Earth plug-in below, or by accessing the Google Earth files directly here. Move the slider to change the date.

Note that these maps take into account the different coastlines at different periods, which is why they may show grassland etc. in what is now sea. The map for the present shows potential vegetation (i.e. as it would be in the absence of human influence). Actual vegetation can be very different due to the effects of industry and agriculture, the main thing being the widespread clearance of forests.

For most of human existence, the climate has been colder and drier than today, resulting in more desert and less woodland. However, around 10,000 years ago, climate was generally moister than today, and the Sahara desert was converted to grassland and steppe. That said, the global environment did not vary as one. Climatic change could, for example, mean a shift in wind patterns, carrying moisture away from one region and towards another, so that the first region became drier and the second one wetter.

Conclusion

This post has provided a narrative of climatic variation over the period of human existence, plus some relevant resources in terms of maps of changing coastlines and terrestrial environments. It has not reached any particular conclusions but is intended to provide the high-level background for subsequent discussion of humans' discovery and conquest of their world.

Specific coastline and development

2008-04-20T17:11:00.016Z

Sea transport was more efficient than land transport throughout most of the development of civilisation - from the late neolithic or early bronze age until today. Coastal areas had higher scale, and were more populous and more advanced than inland regions.

Therefore, other things being equal, regions with a large amount of coastline for a given landmass developed faster and further. Europe benefited from this, since it is a relatively small continent with a long, convoluted coastline. By contrast, Africa and Asia, with smoother, more rounded shapes that encompassed a much bigger area, were at a developmental disadvantage.

We call the ratio of a region's coastline to its surface area, the specific coastline. Values of the specific coastline for various regions are as follows:

Region	Specific coastline (km^-1)
Europe	4.1 x 10^-3
Asia	1.7 x 10^-3
Africa	1.0 x 10^-3
Western Europe	6 x 10^-3

Source: N Rashevsky Looking at history through mathematics (Cambridge, MA 1968) pp. 132-3.

The advantage of Europe, especially western Europe (excluding Russia and Poland), is clear. Its high specific coastline helped it to develop faster than other regions during the last half-millennium of ocean-going transport. This advantage has diminished with the growth of land and air transport, and will all but disappear as humanity transitions to a space-based economy.

Europe - specific coastline = 4.6 x 10^-3

Asia - specific coastline = 1.7 x 10^-3

Africa - specific coastline = 1.0 x 10^-3

Europe appears even more advantaged when we consider the specific river coastline (ratio of total river length to area). For Europe, this is 9 x 10^-3 km^-1, compared with 1 x 10^-3 km^-1 for China, and 5 x 10^-4 km^-1 for India. Europe's total coastline (river and sea) is nearly ten times that of China or India (Rashevsky Looking at history through mathematics p. 133).

The Mediterranean and development

2008-03-02T13:41:00.028Z

I will now discuss the pattern of world development with respect to the model introduced in my last post. You can use the program supplied in that post to reproduce the following discussion and experiment for yourself.

Set up a simple model of the Mediterranean region as shown below.

This uses the default terrain types, representing land, river, coast and sea, as well as the surrounding ocean.

The layout depicts the Mediterranean sea, surrounded by Europe, Asia and North Africa. The regions bordering the sea are designated as coast. The Nile and Tigris-Euphrates river valleys are also represented. However, the main body of Africa is not included, leaving North Africa and the Nile valley as an isolated strip. This represents North Africa being isolated from the rest of the continent by the Sahara desert. (One could include some 'desert' terrain to represent this, but it is easier just to leave the southerly regions as impassable 'ocean'.)

See the diagram below, with red labels showing the terrain types, and white labels showing the geography.

The aim of this experiment is to demonstrate two aspects of historical development:

1. The Nile valley benefited from both its central location and the ease of movement afforded by the river.
2. As (marine) technology improved, the advantage shifted from the river valleys to the regions bordering the sea, especially the Italian peninsula sticking out into the middle of the sea.

We need to make sure the various terrain types have the appropriate properties of habitability and traversibility. The ones we will use are supplied as the default values in the program.

Land, river and coast are assumed to have the same habitabilities. The only difference between them is that coast and river have traversibilities that are respectively 20 and 40 percent higher than that of land. Sea has a habitability of zero, and initially a traversibility of zero. However, when technology reaches a high enough value, the traversibility of sea switches to a value much higher than that of land. The traversibilities (and habitabilities) of land/river/coast do not change at all with technology. This reflects the notion that, over the period we are interested in, roughly 3000 BC to 1 BC, although movement on land improved somewhat, the really significant change was the opening up of sea transport.

Having set up the topography as above, click the button to populate all regions.

Check the Verbose box, to get a display of the status of each region (you may need to move the land to the middle of the map display, so you can see it in verbose mode).

Press Step, to calculate the scale of each region. Compare 'Italy' with the 'Nile delta' (the region of river adjacent to the 'Mediterranean'). You should find that the Nile delta has a higher scale and consequently higher potential technology than Italy (specifically, 0.41 for the Nile delta, 0.142 for Italy, see below).

Now press the Run button and allow the simulation to run till the values for each region have pretty much stopped changing. You should find that Italy has overtaken the Nile delta (potential technologies of 1.739 for Italy, 1.489 for the delta, with both regions probably having reached their potential). The diagram below shows how the development levels of the different regions (Italy, Egypt, Mesopotamia [i.e. Tigris-Euphrates], Levant [i.e. coastal strip at east end of Mediterranean]) change during the run.

Obviously, this model is very crude in terms of the values assumed and the way we have laid out the topography. However, it demonstrates the basic points referred to above: that, with respect to development, Egypt had an initially favoured position and that this advantage shifted elsewhere as technological growth changed the sea from an insulator to a conductor of human interaction.

What happens in the simulation is that, as technology grows (in Egypt and elsewhere), it passes the level that opens the sea up to marine transport. At this point, the regions bordering the Mediterranean receive a boost in scale and in technological potential. For Italy, being surrounded by sea was previously a disadvantage but now becomes an advantage.

If you want to follow the detailed steps by which this change comes about, pause the simulation, click on Clear Population then Populate All again, and just press Step repeatedly.

You may like to create more realistic representations of world topography, including additional terrain types, and experiment with different values for traversibility and habitability.
You could also extend this simulation to model the later shift of advantage from the Mediterranean to the Atlantic rim, once technology growth opened up the ocean.

Italy is not the only land sticking out into the Mediterranean. Greece also does so, and the development of civilisation there preceded that on the Italian peninsula. This reflects its greater proximity to the original centres of civilisation in the near east. See the map below.

View Larger Map

Experimentation with development

2008-02-22T20:54:00.046Z

This program is for exploring some of the ideas in my last post. (Scroll down for explanation.)

(No program? See only a red X? You need to install the Java Runtime Environment (JRE). Click here.)

The above program allows you to investigate how scale and development depend on topography.

The idea is that you can create a land-mass with a particular shape and give it a certain population. This allows you to see how scale varies at different points of the land-mass. Higher scale results in greater development of technology, which permits a larger population and greater ease of movement. Since scale depends on population size and ease of movement, this creates a positive feedback. Having set up your land-mass and initial population, you can run a simulation to watch how things develop.

In the program, the world is divided into a grid of square regions. You create your land-mass by 'painting' different shapes (e.g. oval, rectangle) and different types of terrain (e.g. land, river) on the grid. Similarly, you 'paint' the population on the regions. You can add your own terrain types, and, for each terrain type, define the habitability (maximum population) and traversibility (ease of movement) as a function of technological level. Initially, all regions are set to 'ocean' (pale blue colour).

The traversibility of terrain depends on the technology of the source region. Suppose a region X has a given population. This population contributes to the scale of surrounding regions. To work out X's contribution to the scale at region Y, we have to take into account the difficulty of movement from X to Y, which means taking into account the traversibility of each region between X and Y. In performing this calculation, we use the technological level of X to determine all the traversibilities (i.e. not the local technological level of each region). Conversely, when working out Y's contribution to the scale at X, we use the technological level of Y to work out the traversibilities of the intervening regions. The idea behind this is that a region's ability to project itself depends on its own technology not on the technology of the receiving regions. E.g. America's ability to influence, say, Nigeria depends on American technology (internet, TV, airlines) not on Nigerian technology.

To familiarise yourself with the program, try the following (you may want to open a copy of this window so you can follow these instructions and view the program at the same time):

1. First, we need to activate the applet (program). Click anywhere in the program box to do this. The program has controls at the top, and a display area where you can set up land-masses by painting terrain onto the different regions.

2. To see the regions clearly, click on the check box labelled Grid (top right). You can move the display around by dragging with your mouse, and zoom in/out with your scroll wheel.

3. To create an island in the shape of a rectangle divided into 9 regions with terrain type 'land', do the following:
a. Click on the radio button labelled Rectangle (top left).
b. Click on the button labelled Paint (top centre).
c. Make sure the adjacent drop-down box says Land. If not, select it from the list.
d. Draw a 3x3 square in the middle of the display area by clicking and dragging the mouse. If you make a mistake, click the button Clear Terrain (top right) and try again.

4. To set up each region with an initial population of 100, do the following.
a. Edit the field labelled Population to read 100 instead of 1000 (left hand side of control panel).
b. Click the button labelled Populate All (left of control panel). Dots should appear on the square island. The size of the dot in each region represents the size of the population in that region. (If you want, you can add population to one region at a time, by clicking the Paint button next to the population field, then clicking on the relevant region.)

5. To see the status of a given region of the island, right click on it, and select Region Information from the popup menu. A dialog box will appear with the relevant information. 'Population' is self-explanatory. 'Potential' represents the potential scale generated by all the populations in surrounding regions; the potential generated by each population depends on its size, how far away it is, and the ease of movement between the two regions. 'Scale' is the potential scale multiplied by the population of the region in question; e.g. a large population in region B generates a large potential scale in region A, but, if there is nobody in region A, the actual scale of region A is zero. 'Technology' represents the technological and institutional sophistication of the region; this can reach a maximum level that is a function of the region's scale. 'Habitability' represents the maximum number of people the region can support, given its technological level. Finally, 'traversibility' represents the ease of movement across the given type of terrain. In this case, you should find that the region's population is 100, the habitability is 1000, the traversibility is 0.1, and everything else is 0. Click ok to get rid of the dialog box. If you check the other regions, you will find that they are the same.

6. Now let's look at scale.
a. Click the button labelled Step. This performs one iteration of the simulation and results in the scale of each region being calculated as a function of the populations of surrounding regions.
b. Now click on different regions of the square island and view the Region Information again. Where is scale highest? Where is it lowest? Why is this? You should find that scale is highest in the centre, lowest at the four corners, and intermediate in the remaining regions. This reflects the fact that the central region is overall closest to the other regions, while the corner regions are overall furthest away.

7. Next let's simulate the growth of population and technology. The assumption is that population grows asymptotically towards the level set by the region's habitability, while technology grows asymptotically towards a level that is equal to the region's scale.
a. Select the checkboxes labelled Population and Technology. These variables will now be updated at each iteration of the model. (This feature means you can choose independently whether or not to simulate the growth of population and/or technology, making it possible to isolate one factor and see how it behaves.)
b. Click Step, then inspect the information for each region. You will find that the population of each region has grown by the same amount, but technology has grown to different extents depending on the scale of each region.
c. Let the simulation continue until the populations have just about reached the maximum habitability, which is currently 1000. Rather than repeatedly clicking the Step button, you can click the Run button to do this automatically. The slider to the right of the button controls the speed. Move the slider to the left for the simulation to run faster. (If the simulation seems to freeze, move the slider right to slow it down.)
d. When the centre region's population is say 999.99 (check the region information, as above), click the Run button (now labelled Pause) to pause the simulation. Check all the regions. You will find that the technology in each region is virtually equal to the region's scale, and is therefore highest in the centre, lowest at the corners. The actual values should be about 0.429 for the centre, 0.217 for the corners, and 0.317 elsewhere. If you click Run again, these values will change little, as population has pretty well reached its maximum everywhere.

8. The next thing to learn is how to set the traversibility and habitability for a given terrain type.
a. Make sure that Land is selected in the drop-down list and look at the table labelled Terrain Types. The first row should read Technology=0, Traversibility=0.1, Habitability=1000. This means that, for a technology level of 0 or above, the traversibility and habitability of 'land' have the values indicated.
b. Click in the second row of the table, in the column labelled Technology, and type 0.4. Then edit the values in the second row under Traversibility and Habitability to be 0.15 and 1000 respectively. This means that, for a technology level above 0.4, the traversibility of land is now 50 percent higher, 0.15 instead of 0.1. This represents the fact that a certain level of technology brings innovations like the road, horse-and-cart or motor-car, which allow people to get around more easily.
c. You can also change the colour assigned to a terrain type, by clicking on the coloured rectangle labelled Colour, and create a completely new type of terrain, by clicking on the button labelled New. We won't do either of these in this case.

9. Now let's see what difference it makes that a higher technology level produces a higher traversibility.
a. Step the simulation once then check the information for each region. You should find that the scale and technology level of the central region are the same as before, around 0.429. However, the scale of the four side regions should be found to be higher, around 0.356, while the technology level has also increased, to around 0.321. Similarly, the scale of the corner regions should have increased to around 0.235 and their technology level to around 0.219.
b. What is going on here? Well, the technology level of the central region is above 0.4, so for this region the traversibility of Land is higher than before, 0.15 instead of 0.1. This means its contribution to the scale of surrounding regions declines more slowly with distance, so their scale is higher than it was. However, the technology of other regions is below 0.4, and for them the traversibility of Land has not changed. Therefore their contributions to the scale of the central region are also unchanged. Overall, the scale of the central region remains the same, but the scale of all the surrounding regions has increased. (Note that a region does not contribute to its own scale.) This increase in scale of the surrounding regions means their technology is beginning to increase towards the level allowed by the new scale.
c. Click the Run button and allow the simulation to run for a while, then check the regions again. You should find that the situation has stabilised with the technologies of the surrounding regions at the new higher level corresponding to their scale.

10. Now we will allow technology to increase habitability as well. This will create the situation where the technology of all regions goes above 0.4.
a. Pause the simulation. Go back to the Terrain Types table, and change the habitability in the second row to 1500. This represents the fact that a higher technology level produces innovations like farming tools, which allow more people to survive on the same area of land.
b. Step the simulation and check the region information. You should find that things are much the same as before, but the population of the central region has increased slightly, to move towards the new, higher habitability.
c. Continue stepping the simulation and keep a careful eye on the scale of all the regions. You should find that their scale is increasing. The growing population of the central region is making a growing contribution to the potential scale of its neighbours, and hence to their actual scale. The potential scale of the central region remains the same, since the neighbouring populations are unchanged, but its actual scale is increasing in line with the increased population. And as scale increases in each region, technology level follows.
d. Run the simulation for a while, until it reaches a new steady state. Check the state of the various regions. You should find that the technology level of the central region is now around 1.480, while that of the side regions is around 1.101 and that of the corner regions is around 0.773. You should also find that the population of all regions is around 1500.
e. What has happened? Well, the growing population of the central region increased the scale of the surrounding regions, until eventually the side regions broke through the 0.4 barrier. This increased their traversibility and habitability so they made a much greater contribution to the scale of the central region, and its technology grew accordingly. Both they and the central regions also increased the scale of the corner regions to the point at which they too broke through the 0.4 barrier, further enhancing the scale and technology of the other regions. The result was a great increase in technology and population all round.

You should now know the way the program works, and be able to experiment on your own. Some final points to note are:
a. Rather than drawing a rectangle, you can draw an ellipse, line or single cell. Lines have to be drawn from left to right. (Yes, my program is a bit rough, but it does the job, I hope.)
b. If you want to explore the effects of a coastline, it can be tedious to paint the coast manually (changing regions from land to coast). The Outline button can do this for you automatically.
c. The Verbose checkbox causes the grid to be displayed zoomed in, with the details of each region written in. This is convenient if you want to follow the changing numerical values. On the verbose display, P=population, T=technology (maximum possible technology shown in brackets), t=traversibility (at T=0), h=habitability, p=potential scale, s=scale. The pair of numbers at the top of each cell are its co-ordinates (column, row).
d. Each iteration of the simulation involves 3 sub-steps: calculating scale, technology, and population in that order. There is also a sub-step for calculating migration, but this is currently not modelled and does nothing. You can perform one sub-step at a time by clicking the Sub-step button. The next sub-step to be performed is shown in the box to the left of the button.

I will finish with some technical details of the model. In the next post, I will discuss how the above program can be used to illustrate the relative historical roles of Egypt and Rome.

Technical details...

The model involves 3 calculations--scale, technology and population--and a set of constants.

(1) Scale calculation

I take each region (square) in turn and calculate its contribution to the potential scale of all the other regions. Firstly, I set the potential of each region to zero. For each region, the algorithm is then as follows:

a. Call the source region the region now being processed.
b. Set working_potential of the source region to be equal to its population.
c. Set the current region to be the source region.
d. Let current_potential be the working_potential of the current region. Consider each region to north, south, east and west of the current region, in turn, as the target region. If the target region has already had its working_potential set during processing of this particular source region, do nothing (this occurs if potential has been propagated to it by another route, and stops potential being propagated back the way it came). Otherwise, calculate propagated_potential as current_potential x traversibility / (traversibility_threshold + traversibility), where traversibility is the traversibility of the terrain type of the target region given the technology value of the source region (note, not the current region or target region). If propagated_potential exceeds a fixed threshold_potential, set the working_potential of the target region to be equal to propagated_potential.
e. Consider each region whose working_potential was set at the last step, in turn, as the current region, and go back to step d.
f. Once there are no more regions whose working_potential has been set but not propagated to its neighbours, add the working_potential of each region, except the source region, to its potential. Set all working_potentials back to zero.

The above is repeated, taking each region in turn as the source region. The result is a total potential for each region. The scale of each region is then calculated as simply the product of its potential and its population.

(2) Technology calculation

For each region, I calculate delta_technology from the formula, delta_technology = time_step x technology_growth_rate x (technology_constant x scale^technology_exponent - technology). Here, scale^technology_exponent means 'scale raised to the power of technology_exponent'.

The new technology of each region is then calculated as technology + delta_technology.

(3) Population calculation

For each region, I calculate delta_population from the formula, delta_population = time_step x population_growth_rate x population x (habitability - population). In this formula, habitability is the habitability of the region's terrain type given the region's current technology.

The new population of each region is then calculated as population + delta_population.

(4) Constants

I used the following values for the various constants introduced above:

traversibility_threshold = 1
threshold_potential = 10^-6
time_step = 0.1
technology_growth_rate = 1
technology_constant = 1
technology_exponent = 1
population_growth_rate = 0.0001

Introducing development

2008-01-05T21:30:00.036Z

I wish to discuss development, by which I mean the growth of technology and societal complexity.

The simplest and lowest-tech mode of human existence is that of hunter-gatherers. We can take this as about the zero of development.

There are variations even among hunter-gatherers. The American Indians of the north-west Pacific coast lived in a rich environment, and supported a high population by hunting and gathering. They had villages and chiefs. This contrasts with people like the Kalahari bushmen, who live as isolated, nomadic families and do not produce anything as lasting and ambitious as a totem pole.

Let us therefore propose a zero of development (D) without necessarily being able to point to a society that actually has D=0. Kalahari bushmen and the societies of the Upper Paleolithic must be close, but even they have technology and ways of behaving that an outsider would have to learn and that make their societies at least a little bit 'complex'. Zero development is the 'Adam and Eve' condition, an isolated couple living off the land in complete simplicity and with no technology whatsoever.

While I have characterised development in terms of technology and complexity, these are not independent factors. They are linked in the society's eigenmode. A society with high technology must be complex. Consider the activity involved in a new release of the Windows operating system -- not just the code developers, but the managers, marketers and distributors, the hardware manufacturers, the bankers who process payments between consumers and producers. And while all these people are getting the new software on the streets, they have to be clothed, fed and sheltered, which involves yet more people connected in yet more economic relationships. Conversely, a society that is as complex as that needs high technology, to provide the necessary transport and communications, and to allow a small number of primary food-producers to support the people engaging in all this secondary activity.

We know that a society's complexity is related to its scale (see here for the discussion).

We can therefore say that development is linked to scale in an eigenmode. That is, each societal eigenmode is associated with a definite scale and level of development. Given the scale, we know the society's development level, and vice versa.

This discussion suggests an issue we will have to come back to once we have a basic understanding of development:

Although technology and societal complexity are linked, it is not clear they are in a direct one-to-one relationship. It may be that, within limits, societies with the same technology can vary in complexity, or societies with the same complexity can vary in technology. When, for example, some societies are described as 'underdeveloped', should we understand by this simply 'low in development', or can society's have a development level that is actually below what they ought to have for their given scale/eigenmode'?

What causes development? The case of the Australians suggests that it is not simply an inevitable consequence of time passing.

The eigenmode concept in itself provides little help. It is essentially static, telling us that societies of a particular scale will be developed to a particular extent, but not how societies actually develop and increase in scale. We need to introduce other ideas.

Consider an island that can be divided into five regions: centre, north, east, west and south. And consider three different situations, as follows:

(a) The central region is populated but the rest of the island is empty

(b) All regions are populated, but impassable barriers prevent people in different regions from interacting with each other

In (a), suppose the population is in an eigenmode (for the moment, do not worry about how it got there, and ignore the possibility of migration ). The population has a certain scale, which corresponds to the amount of interaction among such a population crammed into such an area, and it has the proper development level that both results from and permits that degree of scale. The population is therefore in equilibrium and there is no apparent reason why it should not remain in the same eigenmode for evermore.

In (b), all the regions, being isolated from each other, are identical. The population in each region can be in the same eigenmode as (a). Again, there is no reason why it should not remain in that eigenmode forever.

In (c), the central region experiences interactions with each of the four peripheral regions. (For the moment, assume that the peripheral regions are not in direct contact with each other and remain mutually isolated.) This raises the scale of the central region (remember, scale is a measure of societal interactivity). It also raises the scale of each region with which the central region is in contact. However, the central region experiences four external contributions to its scale, whereas the other regions experience only one external contribution each.

In (c), therefore, the scale of all the regions will increase relative to (b) and the scale of the central region will increase the most. By the logic of eigenmodes, the increase in scale will be associated with an increase in development. And the central region will end up more developed than each of the others.

If we go back to (a) and allow the possibility of migration, the population in each of the peripheral regions will grow, as people move out from the centre. The growth of these populations will raise the scale of the source region. Rather than ending with a situation like (b) where all the regions end up at the same development level as the original, central region, we will actually have the situation described in (c), where all the regions are more developed than the central region was and the central region is developed the most.

In our example, the central region experienced the most development as a consequence of the assumption that the peripheral regions could interact with the centre but not with each other. More realistically, the peripheral regions might be able to interact to some extent. Nevertheless, the north, say, would still tend to interact more with the centre than it would with the south, which is that much further away. In general, if we divide a landmass up into regions, some regions will be better placed than others to interact with their neighbours, and will have higher scale and development.

To summarise, the ability of a population to expand into empty lands can produce an overall increase in development while the highest increases in development will be in the more centrally located regions.

We therefore have a simple understanding of why the ancient spread of humans across the earth would not result in a planet populated entirely at the D=0 condition but would both allow development to take place and lead to a patchy picture with more development in some areas than in others. The development of each region would reflect its centrality and its ease of access to other regions (e.g. regions up and down a river would have more interaction and development than regions with a desert between them).

I want to finish with a question, which takes us more deeply into the issues and which we will have to tackle in later posts.

Let us think back to situation (c). Immediately after the barriers are lifted (if we imagine this hypothetical scenario), the population in each region will have the same technological level as before but can interact with more people (i.e. those in neighbouring regions). Interacting with more people is enough to increase scale. However, that then increases development/technology, and, in general, the increase in technology will itself tend to increase interaction. E.g. development could mean the ability to grow more food and support more people or it could mean better transport allowing people to interact over longer distances. Therefore, the development that results from increased scale will in turn produce an increase in scale. This increase in scale will then generate more development, and so on.

What will happen? Two things are possible. Either increases in scale and development will continue to reinforce each other without limit. Or diminishing returns will set in and the increases in scale and development will peter out, eventually reaching equilibrium in a new eigenmode.

The long term prospects for societal development therefore become a question of the nature of the relationship between scale and development. The case of the Australian aborigines suggests that, at low levels of scale and development, diminishing returns dominate and equilibrium is reached. With the world as a whole, the situation is less clear. There has obviously been positive reinforcement to date, but as global scale and development continue to increase their relationship may move into a region of diminishing returns. After all, one might imagine that there are limits to how many people earth can support, and to transportation speeds and communications bandwidth, all of which would set a cap to scale and development. If we get off this planet into outer space, we could break through those limits into a region of continuing positive reinforcement, but what if diminishing returns set in first, causing us to stagnate before we fully master space travel?

Had Australia been the earth's only landmass, it seems humanity might never have developed beyond the level of the aborigines and never got into space. The earth's landmass is much bigger than that, but the question we would like to answer is, is it big enough?

To all corners of the earth

2007-12-28T16:44:00.025Z

Long before Europeans developed an ocean-going capability, humans had reached the furthest corners of the earth. This included not only every continent but even the remote Easter Island, thousands of miles from habitation in every direction. Some other Pacific islands, such as Christmas Island, showed signs of human settlements that had died out before Europeans first arrived.

This tells us something about people. Humanity, like nature, abhors a vacuum. Humans do not naturally stick together and congregate in large numbers. There is rather a continual outward pressure as people try to get away from each other.

The stone age lifestyle, based on hunting and gathering, requires a large amount of land area per person. If human numbers were going to grow, people had the choice of staying where they were and developing more advanced food production technologies (to support more people from the same land area) or move steadily out into virgin territory. In reality, people did not make a conscious choice. Moving to new territory would have seemed like the only option, and it was only when the world had filled up that humans had to confront and solve the problem of feeding more people from the same area of land.

The hunting-gathering lifestyle naturally draws people on. Rather than moving a little each day, hunter-gatherers tend to stay in one place for a while and then relocate in one big jump. It has been said they eat their way out of camp. The longer they stay, the further they have to travel to find new food sources. In a matter of weeks, the daily round trip exceeds twenty or thirty miles, and it becomes necessary to make a major move.

This outward pressure can take people a long way in a short time. It often seems to be assumed that for early humans to migrate, say, a thousand miles would have taken many generations. Yet even in the stone age, people could in principle have travelled from one end of the earth to the other in their own lifetimes. Consider that the circumference of the earth is roughly 25,000 miles. For a stone age person with an active life of 25 years, it would be necessary to travel 1000 miles per year, or under 3 miles per day, to cover this distance. People who follow stone-age lifestyles today can easily do that kind of mileage.

Of course, humans would not have gone directly around the equator, with several oceans in the way. Nor would they have walked directly across the continents, where the way can be barred by mountains and deserts.

Their easiest route would have been along the coastline. Since people reached Australia very early, they may have had simple boats from the very beginning, as they came out of Africa. This would have sped them on their way.

At the beginning of the upper paleolithic, 40,000 years ago, sea level was lower than it is today. This left a continuous land route from Africa to the Americas, with no ice barriers. Here is a map of the world at that time:

The above image was created using a program at the site of Sebastien Merkel. This allows you to enter a given sea level and view the resulting map. Information about how sea level has changed over time is available at this site.

With sea level as above, travel to Australia still required crossing open water. However, this could be done by island-hopping, with each island visible from the previous one. Only the final crossing, of about 100 miles, required a leap into the unknown, but Australia was a large target and people could have spotted it during short sea trips to and from their home base. (Humans could also have arrived at Australia via New Guinea, which was then connected to Australia by land. However, it is believed they did not take that route and New Guinea was settled after Australia.)

I do not accept that humans only gradually diffused through the world. I believe that, following initial speciation in Africa, humans exploded across the planet, so that the world was occupied almost simultaneously at around 40,000 years ago.

We can estimate how long it would have taken people to spread to fill every continent.

Modern hunter-gatherers live at densities of around 1 person per 15 square miles (compared with 67,000 persons per square mile in Manhattan). However, they tend to occupy marginal environments, the best land having been taken over long ago by agriculturalists. Average population densities in the old stone age might have been higher, perhaps as high as 1 person per square mile. Since the habitable area of the world is about 15 million square miles, the total human population of the world, with paleolithic technology, would have been somewhere between 1 million and 15 million.

Let us define the following:

A =	total area of the world habitable by hunting and gathering (say, 15 million square miles)
ρ =	population density of hunter-gatherers (say, 1 person per square mile)
T =	time for an unconstrained human population to double in numbers (say, 10 years, which was observed on Pitcairn Island during the first thirty years after it was settled by the Bounty mutineers)
t =	time

The number of hunter-gatherers that would saturate the world is A ρ, while, starting from a population of 1 (a pregnant woman), the number of humans after time, t, would be 2^t/T.

The time taken to populate the world is therefore given by

A ρ = 2^t/T

or

t = T log₂(A ρ)

Putting in the numbers suggested above, this comes to about 240 years, for humans to cover the planet.

Of course, this figure should not be taken literally. It is just to give us a feel for the issue. A larger starting population (1 pregnant woman is a little unrealistic) would reduce the time, as would a lower population density, while a longer doubling time would increase it. The point is that humanity's spread through the world does not need to have taken a hugely long time, and in fact it is unlikely that it took a hugely long time.

Note that, once the world was fully populated, population growth would have had to stop until technological improvements allowed more people to be supported from the same land surface. Modern hunter-gatherers are adept at keeping their numbers in tune with their environment, or in fact in tune with what the environment can support in its leanest years. There would therefore have been a short population explosion, followed by near-stagnation (until the development of farming).

Three factors would have slowed down human expansion relative to this simple picture:

Obstructions, such as deserts, mountains and waterways. Crossing the Amazon at its mouth, for example, is like crossing the English channel.
Varying ecological conditions. People who knew how to exploit the flora and fauna of one environment (grassland, forest, seashore) would have had to learn new skills to survive in a different one.
Presence of other hominids. Neanderthals and other hominids already occupied the lands outside Africa. Modern humans would have been competing with them for resources, and might for some time have been kept out of their territories by fear or force.

Nevertheless, people could still have reached every continent in a short time, even if actually filling the continents was slower than the simple argument suggests. Having boats and following the coastline, humans would have remained within a familiar environment while being able to bypass obstacles. As for conflict with other hominids, it might even have been a factor drawing the more capable humans onwards.

The problem of the Australians

2007-12-22T21:18:00.001Z

The (aboriginal) Australians worry me.

These folks settled their continent 40 thousand years ago -- or, as many scholars now believe, 65 thousand years ago.

Yet in all that time, they failed to develop beyond the old stone age. They developed no agriculture, metal, or permanent settlements. They scarcely even had clothing.

If Australia had not been discovered from outside, there is every reason to suppose its inhabitants might have remained at the stone age level for ever more -- or until the sun burned itself out.

It is frightening to think that a branch of the human species could have continued in this way forever, never realising its potential, and never knowing anything of the science and technology we have developed.

If the Australians had been typical of humanity as a whole, the human story would have looked something like this...

We can attempt to explain the Australians' lack of development in terms of dark age theory.

Scale (a measure of interactivity) is a critical determinant of a society's institutional and technological complexity. Low-scale societies are inevitably simple, as small groups of isolated people cannot support elaborate economies and political systems. Stuck at the end of the world's main landmass, and separated from it by a lengthy sea-crossing, Australia experienced low scale. It was exposed to few influences. The effective size of the population within reach, i.e. the scale, was too low to sustain development beyond paleolithic levels.

We can refine this argument. For an isolated region, scale depends on the population contained within that region. But the population that exists within the region depends on the technological level (because sophisticated food-production techniques support more people on the same amount of land). And the technological level depends on the scale. What appears to have happened in Australia is that humans achieved an equilibrium, or eigenmode, where technology supported a population that generated enough scale to support that level of technology...and no more. This eigenmode, i.e. self-consistent solution to the problems of social existence, was quite stable and there was no reason why the Australians should ever have broken out of it.

This argument suggests several points of concern:

New Guinea is also small and isolated, yet its inhabitants achieved the neolithic level, unlike the Australians. New Guinea was actually joined to Australia, as the continent of Sahul, until about ten thousand years ago, so why did the Australians not achieve the sophistication of New Guinea? The Polynesian islands are even smaller and even more isolated, yet many had chiefdoms, surpassing New Guinea in sophistication, let alone Australia. We might be able to explain this in terms of humans bringing the relevant technologies and institutions to these islands, so that they were already in a more complex eigenmode. But why were people not able to carry this eigenmode to Australia?
If Australia was too small to support developmental growth like that of the Afro-Eurasian and American world islands, it suggests that, had the world's landmass been more broken up than it is, then humans would not have been able to develop anywhere. The fact that humans have developed must then be seen, in part, as a geographical accident, not an inevitable result of human talents.
Australia is a big place. If we are saying Australia was too small, then just how big does a continent have to be before humans are able to develop beyond the paleolithic? It is true that Australia has large areas of desert, but the Nile Valley is surrounded by desert. And climatic conditions in Australia have changed a lot over the millennia. Why could civilisation not have developed along the valleys of Australia's Orange or Murray-Darling rivers? If we are saying environmental conditions here were never quite right, then just how flukey was the development of civilisation elsewhere?
If Australia reached equilibrium at a technological level commensurate with its size, then could this be the fate of the world as a whole? Will we stagnate at a (much higher) technological level where the planet is able to support just enough population to sustain that level of technology? Could the human race flat-line until the sun goes supernova or something else wipes us out?

The point of these questions is not to deny that Australia's lack of development can be related to its situation, but to show some of the complicating issues that a full theory must take into account and be able to explain.

We should also note two other points:

There is no reason to think, as some might, that the aboriginal Australians lacked the mental capacity of humans elsewhere. All humans today are members of a single species, descended from common ancestors living at most 100-200,000 years ago. On an individual level, aboriginal Australians operate perfectly competently in technologically advanced society; high achieving aborigines include academics, politicians and writers. Australian traditional culture is also sophisticated in its own way; languages and kinship systems are more complex than those of 'advanced' societies; art and mythology are well developed; the boomerang is a clever device; aborigines found honey by gluing feathers to bees, slowing them down so they could be followed. [As far as dark age theory is concerned, the sameness of humans everywhere and at all times is axiomatic. Only when it has proved impossible to build an adequate theory of history on that assumption will the axiom need to be abandoned - we are nowhere near that yet.]
Australians seem to have taken up agriculture at various points, then abandoned it again. Therefore, the situation is not as simple as achievement of an everlasting equilibrium. Stagnation was not total, and perhaps changing climatic conditions sometimes elevated scale sufficiently to promote development in some areas.

Finally, there is the argument of Jared Diamond, in Guns, germs and steel, which is that the move to neolithic (farming) lifestyles depended on the availability of crop plants and domesticable animals. While Eurasia had barley/wheat/rice on the one hand and sheep/cattle/horses/pigs on the other, suitable equivalents in the rest of the world were lacking.

Diamond's argument comes back to the issue of continental size. There is a well-known relationship between the size of an island/landmass and its biodiversity. Hence, the largest continent, with the greatest biodiversity, inevitably had the most suitable species for agriculture. The second largest continent was a runner up, while the smallest continent had too litte variety to provide species with the right characteristics for human exploitation.

This argument is not endorsed by dark age theory, which starts from the assumption that history is a sociological phenomenon, not dictated by random background features such as climatic conditions or availability of domesticable species. In dark age theory, necessity is the mother of invention, so that people would be expected to have found ways of supporting complex society if conditions were right for it. Diamond says attempts to use the zebra as a beast of burden have failed, which he suggests helps explain Africa's lack of development. However, over thousands of years the zebra might have been domesticated as the horse was, had people really needed such an animal. Dark age theory looks for explanations in terms of the inherent logic of human affairs, not in terms of chance, external factors. (This viewpoint may be wrong, but we start from it as an assumption, to be abandoned only when it has demonstrably failed.)

Human speciation

2007-12-09T17:56:00.000Z

I want to discuss why my view of the early migrations of the human species differs from the broad academic consensus.

Firstly, to work out when and how humans came to be distributed through the world, we rely on archaeology and, more recently, genetics. Neither perspective is without its problems.

Archaeology depends on sites. The discovery of new sites may change the picture. Archaeologists are biased towards a constantly changing picture. Careers are made by saying something new and interesting, not by confirming what has long been common knowledge.
Genetic dating depends on mutation rates. These are estimated and, since mutations are random and do not occur at fixed intervals, there is an inevitable margin of error. Furthermore, external factors could have an unknown, systematic effect on the mutation rate. If, for instance, the earth's magnetic field weakened, it would allow more cosmic radiation to reach the surface, possibly elevating the mutation rate.

Archaeologists' and geneticists' models of migration history are evidence-based. This sounds good -- surely our models must be based on evidence -- but means they are subject to caprices of evidence discovery, and uncertainties and revisions of evidence interpretation.

My model is theory-based. Rather than considering only direct evidence for the issue in question, it reflects a broader theory of how human societies operate, based on theories and evidence from a wide range of cultures and historical periods. The point is to build a coherent explanation of the whole of history from a few principles. Incompatibility with specific facts or interpretations, which are subject to the vagaries of academic fashion, does not make or break the theory.

This approach is by no means unscientific. The model makes predictions to be tested against reality. It could be wrong. If it continues to disagree with facts that become increasingly well established, it must either change to accommodate the facts or be abandoned altogether.

I say all this because I choose to start my account of history with a big bang -- the sudden appearance of 'true' human beings in Africa 40 kya (kya = 'thousand years ago'), and their near-instantaneous spread to Europe, Asia, Australia and America. I associate this big bang with a newly evolved ability to manipulate symbols, which I believe underlay art, speculative thinking and 'true' language. In the archaeological record, it corresponds to the transition to the Upper Paleolithic, marked by a new sophistication and variety of stone tools.

My view is by no means original -- the association of a biological event, language skills and the beginnings of human ingenuity was the mainstream view until not long ago. However, it disagrees with some major points of the current academic consensus, which are:

Modern humans appeared in Africa as much as 190 kya. (Nevertheless, it was long believed, and still is in some quarters, that the emergence of the human species was linked to the appearance of the Upper Paleolithic, which is dated to 40 kya)
Australia was settled 65 kya. (This was believed to be 40 kya until the 1980s.)
America was settled about 12 kya. (Increasing numbers of archaeologists think this date should be pushed back at least a few thousand years, with some arguing for dates as early as 40 kya.)

The reason I do not like to believe the human species is as old as 190 ky is that it makes the acceleration of recent times look even more extreme. If it took 150 thousand years to make the step to the Upper Paleolithic, but a hundred years to develop electricity, computing and space flight, it seems we really are in the grip of a runaway process and it can be at most a few thousand years before we conquer the entire universe -- something I find hard to accept.

Such an early date for human origins -- and the implied slowness to move outside Africa and colonise the rest of the world -- also makes humans look much less adventurous than I believe we are.

My prejudices therefore lead me to identify human speciation with the beginning of the Upper Paleolithic -- the point from which growth of mastery over this planet seems to have been almost continuous.

This belief in a link between new technology and a new species can nevertheless be very reasonably criticised. Oppenheimer points out that there is a vast technological gulf between industrial societies and, say, the tribal societies of highland New Guinea, yet both are composed of fully modern humans. There is no compelling reason why the technological revolution of the Upper Paleolithic should have been associated with a step forward in biological evolution.

So I cannot really justify my choice of starting point. All I can say is, let us run with it and see where it gets us.

Genetic trees and the peopling of the world

2007-10-15T18:15:00.002Z

I would like to go back to discussing how humans spread through the world.

Numerous books have appeared on this subject in recent years, stimulated by new techniques of genetic research. I find these interesting but I question their claimed definitiveness.

Imagine photocopying documents, where you photocopy the photocopies, perhaps making dozens of copies from each copy. In the course of this, blemishes will occasionally appear. When you photocopy the blemished copy, the same blemishes will be reproduced in all subsequent copies. If you look at two copies and see that they share the same blemish, you know they must "descend" from the same original, blemished copy. If you also see that the two copies have additional, different blemishes, and you know how often blemishes arise--say, once every thousand copies--you can work out how many copying generations it is since the copy from which they are descended. E.g. if they differ by three blemishes, it must be three thousand generations since the "ancestor" photocopy passed through the photocopier.

Photocopier genetics

A similar principle has been used to determine the family relationships between human populations.

It does not work with ordinary DNA, which is mixed and matched at every generation (half from each parent) by sexual reproduction--as if the photocopies were cut in half and taped together in new combinations, so that blemishes are spread around and clear distinctions between lines are not maintained.

Instead, it relies on parts of the genome that do not undergo recombination. These are mitochondrial DNA, which people inherit only from their mother, and the Y-chromosome, which is passed down intact (or almost so) from father to son. When these genes are passed down, copying mistakes occasionally occur, so that people today show many variations deriving from ancient errors. As with photocopier blemishes, such variations make it possible to estimate how long ago any two people shared a common ancestor (female ancestor for mitochondrial DNA and male ancestor for the Y-chromosome).

Stephen Oppenheimer, in his book Out of Eden: the peopling of the world, describes how geneticists have used this principle to trace the ancestral connections between human populations and to work out how long ago they split off from one another.

The message he likes to convey is that archaeologists and historians were fumbling around in the dark until these new genetic techniques came to shine the clear light of day on their disciplines.

For instance, the geneticists have apparently instantly and conclusively resolved an issue that archaeologists might have been arguing about until kingdom come. While archaeologists once saw changes in the distribution of pottery as indicating the wholesale movement of the people who produced the pottery, more recently they have argued that people remained put and only styles and technology spread from one region to another. The genetic evidence seems to show that, indeed, most modern populations have been where they are for a long time and the formerly hypothesised migrations never took place.

Nevertheless, I suspect that, in the fullness of time, the geneticists' arguments will come to seem as problematic as those of the archaeologists' and historians', which themselves once seemed so obvious and compelling. It will be revealed that there are other ways of interpreting the results and doubt will creep into this young discipline where today certainty is supreme.

After all, according to Oppenheimer, the entire non-African population of the world is descended from a single group that left Africa via the Arabian peninsula about 80,000 years ago. Yet the notion that, over the entire lifetime of the human species, no other people had the idea of leaving Africa is hard to credit. Right there lies a reason for having doubts about the completeness of the genetic picture.

Even if the geneticists prove to be completely correct in their picture of ancient population movements, there remains a vital role for historians and archaeologists in advancing understanding of the past. The things that make, say, Britain what it is today are Magna Carta, the Elizabethan Age, the Civil War, the Industrial Revolution, and so on--i.e. sociological things that are not passed down in our DNA. History and society, the concerns of this website, are the subject of cultural, not genetic, transmission, and the connection between genes and culture is probably looser than people like Oppenheimer tend to assume.

The path of civilisation

2007-09-01T18:32:00.000Z

For most of history, waterborne transport was easier and quicker than movement overland.

Scale was highest in the vicinity of waterways, where people were more mobile and could get in touch with each other more easily.

The first civilisations or city-level eigenmodes ("civilisation" = "city-based society") emerged along rivers. These included the Nile valley (Egypt), the Tigris-Euphrates basin (ancient Iraq or Mesopotamia), the Indus valley (or Harappan civilisation) and the Yellow River (China).

Early state formation was along rivers, where mobility, i.e. scale, tended to be higher

As the technology of water transport improved, the cutting edge of civilisation shifted from rivers towards seas, notably the Mediterranean...

The 'middle sea'--a relatively benign, tideless sea--facilitated societal intercourse and was the focus for the next stage of civilisation

...and then from seas towards oceans...

Improvements in navigation took trade and interaction to the next higher level, favouring those regions bordering the Atlantic ocean

This logic was interrupted by the development of railways, highways and air transport, all of which diminished the advantage of societies bordering on water.

As technology continues to develop and humans build a space-going civilisation, the advantage will shift again towards those regions where it is easiest and cheapest to launch rockets into orbit. These are the equatorial regions where the boost from the earth's rotation is biggest.

As humanity moves into space, scale will be highest along the equator, where launching rockets is easiest, and the centre of civilisation will move once again, towards this belt

That civilisation is most advanced where scale or interactivity is greatest means that, if there are other intelligent races beyond this planet, then they are most likely to be found in the vicinity of galactic cores, where stars are closest. I have stated before that I think humans are probably alone in the universe but, on the basis of this historical theory, I would urge SETI researchers, if they are going to look for extraterrestrial life, to concentrate their attentions where worlds are densest.

Summary - understanding social complexity

2007-08-12T21:05:00.000Z

I want to summarise the points I have been making in the last half dozen posts.

When we look around the world, we see societies of varying sophistication.

We should not put this down to some societies being more 'talented'. It is a matter of scale and eigenmodes.

The question is, why scale increased in some places and not others.

We should not think that increasing scale is an obvious 'choice'. People actually like to get away from each other. And the simple, free lifestyle of low-scale societies holds many attractions.

That said, people are contradictory. Population concentrations can be attractive, offering possibilities not found in the free-roaming band, especially as far as young people are concerned. Once established, high scale may be self-sustaining.

Why there are three eigenmodes

2007-07-08T15:57:00.000Z

I previously introduced the family, village and city-level eigenmodes of society. What differentiates these societies is the relative probability of meeting friends, acquaintances and strangers.

At the family-level people deal almost exclusively with friends. Encounters with people that could be regarded as acquaintances or strangers are rare.
At the village-level people, if not friends, are at least acquaintances. Encounters with strangers from outside the village are rare.
At the city-level people, most people are mutual strangers and encounters with strangers are normal.

Since even in the city people have acquaintances and friends, the village and family are actually subsets of the city eigenmode. People who live in city-level societies also belong to village-level and family-level societies. (This need not be a literal village; the 'village' may consist of a neighbourhood or a group of co-workers in a company.) Similarly, people in village-level societies also routinely experience the family-level.

The relationship between scale and the different eigenmodes can be attributed to the fact that maintaining acquaintanceships and especially friendships requires an investment of time, yet people's time is limited. If they encounter thousands of people over the course of a year, they cannot really be acquaintances let alone friends of all of them.

The number of friends a person may have is from about ten to about fifty (remembering that 'friends' in the technical sense includes close relatives). The number of acquaintances may be from about a hundred up to about a thousand. All other relationships are strangerships.

As the society's scale (interactions per unit time) changes, the proportion of friendships, acquaintanceships and strangerships changes as shown in the following figure.

When scale is very low and people spend all their time with say ten others, all relationships will be friendships. Friendships=100%, acquaintanceships=0%, strangerships=0%.
As scale increases and people each maintain say a hundred relationships, ten of those relationships will be friendships and the other ninety acquaintanceships. Friendships=10%, acquaintanceships=90%, strangerships=0%.
As scale increases further and people each maintain say a thousand relationships, ten of those will be friendships, a hundred acquaintanceships, and the other 890 strangerships. Friendships=1%, acquaintanceships=10%, strangerships=89%.

Thus, as scale varies, one passes from a friendship-dominated society to an acquaintanceship-dominated and then strangership-dominated society. Since friends, acquaintances and strangers behave towards each other in different ways, the type of relationship that dominates a society determines the type of behaviour that is characteristic of that society.

Friends, acquaintances, strangers, and the three dimensions of society

2007-06-30T21:50:00.000Z

Friends, acquaintances and strangers behave differently with respect to the three dimensions of society.

These differences are summarised in the following table and explained below.

	Friends	Acquaintances	Strangers
Political	Equality	Prestige	Domination
Economic	Sharing	Credit	Exchange
Social	Personal contact	Community	Abstraction

Friends

Political dimension. This scarcely exists. Among friends there are no power relations. Some may be respected and listened to in particular situations, but none are allowed to put themselves above others. There is equality.
Economic dimension. There is no concept of debt or of the exact measuring out of how to pay someone back for a service they have provided. Instead, there is an attitude of share-and-share-alike. Everybody pools what they have and all get equal benefit from the common stock. This has been called 'primitive communism'. In sum, there is sharing.
Social dimension. People know each other on the most intimate terms, often as close relatives or at least as very close friends. Their loyalty to each other is based on this direct emotional bond. What connects the members of the group is personal contact.

Acquaintances

Political dimension. This is relatively weak, but certain people have influence over others, obtained through the force of their personality. They must work hard to keep up their authority over networks of clients whom they place under their obligation either with material support or by brokering activities on their behalf. It is their personal qualities and activities that cause them to be listened to. The ability to determine the behaviour of others is based on prestige.
Economic dimension. People trust each other and do not demand immediate repayment for goods or services that they might have supplied. Nevertheless, there is a requirement that exact repayment should be made in the long run. People who have been given help owe something to those who helped them. The system of exchange is based on a concept of credit.
Social dimension. People know each other by sight. Even if they are not friends directly, they are connected through others. They share a way of life down to every detail of language, dress and custom. They call the same general area home. They participate in the same festivals and public activities. There is a sense of community.

Strangers

Political dimension. Some people have power over others, based not on personal charisma but on the threat of force. There is a pyramid or hierarchy of power and power-holders are supported by the rest of the hierarchy, so that power can be assigned to the very young or old or others who could not secure it on their own behalf. Since the hierarchy mobilises to protect itself and imposes its will rather than merely exerting influence, power is experienced as domination.
Economic dimension. People are not prepared to give credit to those they cannot be sure of meeting ever again. When they give each other services they require immediate satisfaction in the form of a counter-service of equivalent value, and they expect nothing further in future. Every transaction comprises a balanced and completed exchange.
Social dimension. People do not necessarily share things in common. They may dress differently, speak differently, behave differently. Their sense of home may be different. In so far as they feel part of one group it is by acknowledge loyalty to a flag, a figurehead, a nation or some other abstraction.

Friends, acquaintances and strangers

2007-06-17T12:34:00.000Z

Hunter-gatherer or family-level societies are characterised by sharing and egalitarianism.
This means that...

Sharing: people readily lend or give away food and possessions, and, instead of precise reckoning of debts, there is a general expectation of give and take. This does not mean that people are always happy to share. They can find it a burden. Fred Myers, who studied the Australian Pintupi tribe, once lost his temper when he ran out of cigarettes because the aborigines had cadged them off him. One of his aborigine contacts advised him to hide his cigarettes in his sock and pretend that he did not have any next time he was asked, saying "that is what I do".
Egalitarianism: there are no definite leaders and those who try to dominate are shunned or mocked. Richard Lee, who studied the Kalahari San, once tried to thank his hosts by giving them an ox to feast on. Instead of showing gratitude, they teased him, saying what a measly ox it was. In this way they prevented the appearance of any feelings of superiority/inferiority caused by his obviously greater wealth as a western anthropologist.

Anthropologists have contrasted such attitudes with the selfish and hierarchical nature of 'developed', or high-scale, societies, where shopkeepers do not share food with their customers and where politicians exercise power over other people's lives.

A moment's thought reveals, however, that members of high-scale societies behave like hunter-gatherers when it comes to those closest to them. Inside the household, there is sharing and equality: shopkeepers are not mercenary at home, nor do politicians lord it over their family in the way they show their authority in public.

The selfishness and hierarchy that seem typical of high-scale societies are characteristic of how people deal with strangers. It is just that, among hunter-gatherers, meetings with strangers are rare. Nevertheless, when they do have to deal with strangers, hunter-gatherers do not go in for their normal casual sharing. For example, they conduct trade with other groups, and, although this can take on what to us are unfamiliar forms (owing to communication barriers, lack of a medium of exchange, and mutual suspicion/hostility), it boils down to immediate and balanced exchange just like trade in high-scale societies.

Therefore, rather than hunter-gatherers and citizens of 'developed' societies having fundamentally different attitudes to sharing/not-sharing, they can be regarded as having exactly the same attitudes. The difference is in the amount of time they spend dealing with strangers versus friends and relatives.

How one person acts towards another depends on two factors:

Intimacy: whether the person is only happy if the other person is happy
Trust: whether the person expects to meet the other person again

These factors combine to produce three different types of relationship:

Relationship
Intimacy
Trust
Friendship
Yes
Yes
Acquaintanceship
No
Yes
Strangership
No
No

Some comments on this model:

A 'person' is not necessarily an individual human being, but can be any legal or corporate 'person' such as a business firm or a nation state.
The terms introduced above have the technical meanings given to them, not their natural meanings in informal, everyday language. For instance, a mother would be considered her son's friend in the above technical sense though probably not in the everyday sense. Similarly, a person's bank would be that person's acquaintance in the technical sense, in that there is an expectation of meeting again (they have each other's address) = trust.
The above table leaves out a fourth possible relationship, involving intimacy but no trust. One might think that such a relationship would never occur and that intimacy would always involve trust. However, this relationship is seen when people give charity towards those they do not know and do not expect to see again. A classic example is that of desert tribespeople accepting unfamiliar travellers into the camp and giving them food, water and shelter. The hosts do not expect direct recompense, but they do expect indirect recompense through being treated similarly when they are travelling and in need of refreshment. I will not make much use of this relationship.

Three dimensions of society

2007-06-02T07:16:00.000Z

When characterising eigenmodes below, I described the typical behaviours of each society under three headings: political, economic and social. These may be defined as follows:

Political: power relations, or the ability of some parties to control the activity of others.
Economic: mechanisms for distributing scarce resources through exchange of goods and services.
Social: perceptions of unity, mutuality and membership of groups with definite identities.

These three dimensions of society have long been recognised. They are common in everyday speech as well as in academic work.

Some people talk about the dimensions using different terminology, perhaps of their own invention. For example:

	Political	Economic	Social
Rudolf Steiner (philosopher)	Political	Economic	Spiritual-cultural
Arnold Toynbee (historian)	Political	Economic	Cultural
Pitirim Sorokin (sociologist)	Compulsory	Contractual	Familistic
Kenneth Boulding (economist)	Threat (do this or else)	Exchange	Integrative
Peter Cruttwell (independent theorist)	Power	Subsistence	Metaphysics
Guy Siebold (defence scientist)	Vertical	Horizontal	Organisational or social

It does not really matter what we call them. The important thing is to recognise that collective human behaviour has these three distinctive aspects.

The reason why some writers prefer 'cultural' instead of 'social' is perhaps that 'social' can be used in a general sense to describe all collective behaviour, including the political and economic. However, the phrase 'political, economic, social' is well established and, so long as we are aware of the issue, it should not cause any problems. Context is enough to indicate which sense is meant in a particular case.
Note also that, as Steiner's and Cruttwell's terminology implies, 'social' or 'cultural' implies ideological aspects. To be part of a social group means to subscribe to values and beliefs that characterise that group, including religious, spiritual or metaphysical ideas.

It is worth remembering the ancient Greek and Latin origins of these terms:

Term	Origin	Meaning	Comment
Political	πόλις (polis)	city	The city is the focus of power relations, where elites have their governmental bureaucracies or where people come together to argue, debate and seek office.
Economic	οίκος (oikos)	household	The household has to feed and provide for itself, through its own production and through exchange in the market.
Social	socius	friend	Friends share their outlook on life and feel themselves bound together with a common interest and obligations of mutual support.

Some theorists have denied the three-dimensional model.

The sociologist Talcott Parsons supplemented the model with 'military' and 'religious' dimensions. However, military affairs could be seen as an aspect of the political dimension, in its widest sense of power relations, while religion could be seen as an aspect of the social dimension, in its widest sense of common identity and group membership.
'Rational choice theory' contends that all behaviour can be reduced to just one dimension: the economic. According to this, people obey the law or help out loved ones because of what they get out of it, i.e. the benefit of not being punished or the sheer pleasure of being kind and loving. However, this fails to deal with the common-sense perception that a motorist stopping at a traffic light or a mother feeding her baby is engaging in a different kind of activity from buying and selling in the market. With rational choice theory everything interesting is treated as a trivial background assumption about what people would prefer, whereas the behaviours giving some people power over others or giving others a sense of shared interest are really what we need to model and explain.

In science, a theory or model cannot be judged by its correspondence to some intrinsic or absolute truth. Even if such absolute truth exists we do not have access to it. Instead, we must judge theories by how useful they are. It is therefore not a case of Parsons or rational choice theory being 'wrong' and the three-dimensional model being 'right', but of which is richer and more satisfying in describing human sociality. The three-dimensional model is consistently popular in this respect, while that of Parsons has not been taken up and rational choice theory is less in vogue than it was. Nevertheless, the model's merits will not be found in a priori arguments, but depend on its ability to deliver worthwhile results.

Important. Although these three dimensions can be distinguished from each other theoretically, they are mixed together in actual human behaviour. For example, tax-paying is compulsory and therefore belongs to the political dimension, but there is an element of exchange, in that taxpayers receive benefits in return for their taxes, and they are perhaps motivated too by a sense of community responsibility, so that the economic and social dimensions are also involved. It is rare, if not impossible, for an activity to be classifiable as purely political, purely economic or purely social.

Scale

2007-06-02T07:14:00.000Z

In characterising the three basic eigenmodes, an important factor was the size of the community. I argued, for instance, that a small group of hunter-gatherers could not support the social complexity of a large city.

However, it can be difficult to define the size of the community.

Although the San split into groups of about a dozen adults most of the time, they come together in bands of fifty or more for festivals or rabbit drives.
A city like New York not only belongs to a larger nation, but need not have clear-cut boundaries and includes people who commute in and out during the day.

The important issue is people's ability to interact. The point about the city is that people come into contact with perhaps thousands of people over the course of a year, so that they can access all sorts of specialist services and find enough customers for their own specialist skills.

This is captured by the concept of scale:

The scale of a society is the number of distinct persons with whom a member of that society interacts in a given time.

The advantage of this definition is that we do not need to worry about how to draw the boundaries of the society.

Some theories (e.g. A W Johnson and T Earle The evolution of human societies) talk in terms of population density. However, it is not just the number of people per square mile that is important, but their ability to interact with each other, and this can be affected by transport and communications improvements, which bring people into contact without them necessarily living closer together physically.

The scale concept properly captures the importance of the community's size and density along with people's ability to move and communicate.

Emil Durkheim called this dynamic density.

'Interaction' should be interpreted in a very general sense. It does not just mean interaction with people we know.

A fleeting encounter with someone serving in a shop is an interaction.
Someone reading a plumber's advertisement in the yellow pages can be an interaction, since there is a flow of information from the plumber to the reader.

A society's scale is the key to its eigenmode (figures in brackets below represent scale in terms of the number of distinct persons encountered per year).

Low scale (10s of persons) -> family mode
Medium scale (100s of persons) -> village mode
High scale (1000s of persons) -> city mode

Although scale is closely connected with eigenmode, it would be wrong to say the society's scale causes its eigenmode. Scale is an aspect of the eigenmode. We should not think of it as coming first, even though we might want to. It is not productive to think in terms of cause-and-effect but instead we should think in terms of interdependency.

With the definition of scale given above, the comparison between two societies depends on the timescale used.

If we take scale as the number of distinct persons encountered per day, then it might be around 10 for both a hunter-gatherer and a New Yorker, but if we take scale as the number of distinct persons encountered per year, then it might still be around 10 for the hunter-gatherer but in the 1000s or even more for the New Yorker. In other words, if we use a day as the time interval, the scales of the two societies seem similar, but if we use a year they seem very different.

Although we could adopt say a year, which gives a reasonably realistic result, as the standard time span, it would be preferable to have a measure of scale that does not depend on time span.

Let Z_ij(t) be the amount of time that the i^th member of the society spends interacting with the j^th member of the society during a period of time of length t. Define z_ij by

z_ij represents the proportion of time, taken over the long term, for which this member of the society interacts with the j^th other member. The society's scale from the perspective of this member is then given by

The society's overall scale, S, is the mean of the scales from the perspective of each member. If N is the number of persons in the society:

With this measure, some possible scale calculations are as follows (these are simplified illustrations and are not meant to be fully realistic):

Family of 10 persons; people divide their time equally between the other members.	Scale = 1
Village of 1000 persons; people spend much time within a close family group of 10 members and encounter other members of the village one tenth as often.	Scale = 2.9
City of 100,000 persons; people spend much time within a close family group of 10 members, encounter a wider circle of 1000 colleagues one tenth as often, and encounter the remaining citizens one thousandth as often.	Scale = 4.2

Calculations in the above table use base-10 logarithms. This is not important; using other bases will change the absolute but not the relative values.

Three great eigenmodes

2007-05-22T20:19:00.000Z

Societies have existed so far in three basic eigenmodes. (Some might argue for a fourth eigenmode; see below.)

I have described two of these eigenmodes already: hunter-gatherers such as the San, and cities such as New York. The third eigenmode is intermediate between these two. It consists of societies whose members grow their own food and live in isolated settlements with no formal governmental structures.

Let us characterise these eigenmodes more closely...

Family-level	Example: San Size of typical community: 10 people Political mechanisms: Egalitarian; no formal leaders (elders may be respected). Those who try to 'act big' are mocked and resented. Friction/conflict is resolved by one party moving away to join friends, relatives or in-laws in another group (or by violence). Economic mechanisms: Foraging (living off the land); nomadic; very simple equipment. Philosophy of share-and-share alike. Intricate customs give members rights to specific parts of the day's catch. Those who do not 'pull their weight' are subject to teasing and gossip, but there is no explicit reckoning of debits and credits. Social identity: Each family-level group considers itself part of a tribe of several hundred people, coming together a few times per year.
Village-level	Example: New Guinea highlands Size of typical community: 1000 people Political mechanisms: 'Big men' attain prestige through ability, hard work, accumulating wealth and careful cultivation of social networks. They wield influence not formal power. Disputes lead to feuds, where a man allies with his brother against his cousin, and with his cousin against a more distant relative. Big men or priests mediate to break the spiral of violence. Economic mechanisms: People farm/garden. They help each other, e.g. in harvesting/housebuilding, but debts must be repaid (perhaps many years later). Elaborate displays of generosity gain prestige. People are self-sufficient and specialisation is rudimentary. Social identity: Kinship (degree of relatedness) dictates people's obligations and behaviour towards each other.
City-level	Example: New York Size of typical community: 100,000+ people Political mechanisms: Leaders exert formal power, promulgating laws and enforcing them via police and law courts. The position of leader and the hierarchy of officials are permanent, though the individuals fulfilling these roles may change. Economic mechanisms: People are specialists and must exchange with others to obtain the necessities and luxuries of life. These exchanges are commercial transactions, in which there is an explicit and immediate balancing of value. The political authority demands a share of economic output (tax), to spend on public goods like defence, roads and social security. Social identity: People can be themselves; this contrasts with other modes, where everyone knows everyone else's business, family and background.

If you brought some ancient Romans to modern New York and asked them to buy a bottle of win in a shop, then, apart from the language issue, they would understand exactly what was involved. They would be familiar with shops and money. They would also recognise other aspects of the city such as street signs, public and private buildings, and even wheeled vehicles (though they might be surprised at these being self-propelled).

By contrast, if you brought to New York some people who had lived all their lives in an isolated New Guinea village and asked them to buy wine in a shop, they would have little idea what you were talking about. They would find the whole environment of the city unfamiliar and bewildering.

(Nevertheless, a New Guinea highlander might be at home with particular pieces of technology, such as a transistor radio, where the Roman would not have a clue, so this is not an issue of mental capacity.)

This reflects the fact that the ancient Romans, though they lived two millennia ago, were in the same social eigenmode as modern city-dwellers, whereas the inhabitants of a 21st century village cut off in the highlands of New Guinea, are in a different eigenmode.

Some might say that there should be an intermediate eigenmode, that of the 'chiefdom', between the village and the city. A chief's authority is more permanent and formal than that of the village big man, but less formal than that of a city government. For example, the chief collects tribute, unlike a big man, but this falls short of a proper taxation system. However...

While the chiefdom is indeed distinctive, the existence of three basic eigenmodes can nevertheless be accounted for by factors that I will explain shortly (in another post). I therefore prefer to see chiefdoms as eigenmode "2½" (with the village as 2 and the city as 3).
Although there are three basic eigenmodes, there may be many variations on them. A Roman city has its basic features in common with a modern city, but in detail obviously there are differences. Both are eigenmodes in the sense of being self-consistent solutions to the problems of social living. However, in comparison with Rome, the modern city solves the problems with more extensive economic specialisation, more effective policing, higher population density, and a greater ratio of urban to rural population.

It remains a valid question whether there can be a fourth eigenmode beyond the three outlined above, i.e. one that has not yet been realised. I believe the answer may be yes, but I need to discuss other things before I can talk about this properly.

Eigenmodes

2007-05-22T20:17:00.000Z

In my last post I talked about the lifestyles of New Yorkers or San hunter-gatherers as being each a self-consistent solution to the problems of social living.

I call such a self-consistent way of life a social eigenmode.

'Eigen', from the German, means 'characteristic'. An eigenmode is therefore a characteristic mode of social living, i.e. one that is feasible/allowable as opposed to impossible/inconsistent. (This use of the prefix is derived from mathematics. An eigenvector of a matrix is a vector whose direction does not change after multiplication by that matrix; in this sense the vector is characteristic of the matrix.)

Let us put this symbolically.

Suppose a society's way of life (mode) is designated by M, which includes technology, population density, customs and everything else that describes how the society's members live.

Such a society is then exposed to the problems of social living, e.g. obtaining sustenance, caring for the young, resolving disputes and so on. These problems challenge or 'act on' the society's mode of existence. Let us represent this by P(M).

If the society's way of life is not a successful solution to the problems of social living, the society will necessarily change to a different way of life, say to M'. Let us write this as P(M) -> M'. If M' also does not solve the problems, the society will need to change again, say to M''. I.e. P(M') -> M''.

A social eigenmode is a value of M that satisfies the equation P(M) -> M. A mode that satisfies this equation is one that solves the problems of social living and does not need to change in response to those problems.

An eigenmode is therefore an attractor of the operator P(). [At least, if the operator P() has attractors, they will be eigenmodes.] What this means is that any given mode of existence will evolve, under repeated exposure to the problems of social life, towards one of the allowable and self-consistent eigenmodes successfully solving those problems, and there it will stay.

Societies and self-consistency

2007-05-15T21:02:00.000Z

The Namibian government was recently criticised for its treatment of the San or Bushman people, hunter-gatherers living in the Kalahari Desert. It had forced them to leave the desert and give up their traditional lifestyle. According to the government, this was so that the San would undergo development and become part of mainstream Namibian society. The San and their supporters said that the government's real motive was to facilitate exploitation of the desert's mineral resources. A court case found in favour of the San, although the dispute will no doubt go on.

Kalahari San (Bushman)

There is a tendency to think of people like the Kalahari San, whose way of life is essentially that of the Upper Paleolithic, as cases of arrested development. It seems as though their society, unlike our own, has failed to progress. They appear to be living fossils, hangovers from the stone age. It may even be thought that the dark-skinned San lack the intellectual resources of the white races, whose technological civilisation now dominates the planet.

Such ideas need to be put aside...

On the racial issue, the Sami, or Lapps, of Norway and Sweden are fair-skinned, have been hunter-gatherers in modern times and remain so, in part, to this day.
Rather than being a hangover from the stone age, the San may have taken to their way of life in the Kalahari only a few centuries ago, fleeing from slaveraiders and European colonists.
The San are just as keen and capable at dealing with modern technology as people belonging to western society. And the average person in western society had no more involvement in developing advanced technology than did the Bushman in the following picture.

San hunter with GPS device

Nineteenth and early twentieth century anthropologists thought in terms of a ladder of social evolution. At the bottom were 'savages' like the San. Next came 'barbarians', who farmed rather than hunted for their food but were otherwise self-sufficient with a simple lifestyle. Above these were 'chiefdoms', and finally 'states' or 'civilisations', with formal governmental structures and complex economies. Societies were presumed to progress through the successive stages.

It might be thought that this website has a similar view of 'progress'. In an earlier post I showed history as a graph of upward movement towards ever higher Kardashev levels. It is true that I consider human destiny to be mastery of the universe, and since we started from nothing there has to be a process of growth or development to get from here to there. However, we are not 'better' or 'cleverer' than stone age people (past or present). Different ways of life are sensible and successful solutions to the circumstances in which people find themselves, while the dynamic that propels societies from one to the other has a rationale of its own--it is not simply the piling up of inventions by particular brilliant individuals. We should not confuse societies with the people that live in them. The greater complexity of some societies can no more be attributed to them being composed of more capable human beings than the greater complexity of some biological organisms can be attributed to them being composed of more capable molecules.

The way of life of the San and other hunter-gatherers has a logic to it...

Since they live off the land, the San must form small, widely-spaced groups and move regularly in pursuit of food. Most of the time, they separate into bands of no more than ten adults and roam territories hundreds of miles across over the course of a year. The San could not live in a group of 100,000 people because such a group would instantly devour any patch of berries or colony of rabbits it came across. A city-sized community of hunter-gatherers would have to move impossibly far and impossibly often in order to support itself.
Meanwhile, since the San live in such small groups, their way of life has to be very simple. Think about all the expertise and labour that goes into building a car, or setting up a GPS network. An isolated group of ten people, however capable or intelligent, could never undertake projects of this kind. To have, say, a motor industry you need a large number of people, with some mining the raw materials, others designing and assembling the product, and still others growing the food to keep everyone alive.
Finally, since they move around so much and carry everything with them, the San's way of life again has to be very simple. Instead of transporting a drinking beaker everywhere, for example, it is easier just to cup your hands.

Therefore, San communities must be small and mobile because they live simply. And the San must live simply because their communities are small and mobile. The two things go hand in hand.

Contrast this with the situation of New York...

A huge, settled population like that of New York cannot live directly off the land. It has to have an elaborate economy. It needs a large number of specialists doing and making the things without which New York could not function--food retailing, plumbing, building, policing... At the same time, all the complex things that go on in New York, such as stockbroking or providing an underground train service, require the co-operation of a large, dense population.

So New York's large size goes hand in hand with its technological complexity, just as the small size of San groups goes hand in hand with their simplicity.

You cannot mix and match the characteristics of the two lifestyles.

The San lifestyle is incompatible with, say, advanced plumbing, just as the New York lifestyle is incompatible with the lack of advanced plumbing.

If for some reason New York's economy were dismantled and the population were forced to become self-sufficient hunter-gatherers, life in the city would become intolerable. The inhabitants would quickly flee the city and spread across the landscape in search of food. It would not be long before they were back to the San way of life.

Rather than thinking in terms of backwardness and advancement, we might see the San and New York lifestyles as alternative, self-consistent solutions to the problems of social living.

When we look at the San lifestyle, we should not regard it as indicating a failure of intellect or imagination but should recognise it as one of the possible ways that humans may live, whose simplicity is one of its inevitable and essential characteristics.

It might be objected that the San's lack of movement towards a more complex, 'civilised' eigenmode is a kind of backwardness. However...

Since the San reject the town-life that the Namibian government wants to force on them and have campaigned to go back to the desert, it is clear that they prefer their desert lifestyle. They enjoy hunting and gathering, which gives them all the food they need, for a few hours work a day, while in the desert they are freer than they would be in civilised society, where they would have to obey laws and pay taxes.
The complex lifestyle of civilisation can be seen as something that was forced on people when hunting and gathering became untenable, rather than as a product of greater cleverness. Civilised people are not necessarily better off than the San. Many still idealise and hanker for the simple, self-sufficient life. Hunting, for example, is often the prerogative of a privileged elite, while gathering, such as blackberrying, may be done for pleasure.

My main aim in this post has been to introduce the idea that all the features of a particular way of life fit together in a logical manner. As a subsidiary point, I have wanted to challenge the notion that social sophistication should be put down to the greater inventiveness of certain races accumulating over time. Rather than ranking societies on a ladder of progress, we will understand them better if we approach and explore them as individually self-consistent systems.

Outward pressure

2007-04-29T13:04:00.000Z

Easter Island is a triangular speck in the Pacific Ocean, over a thousand miles from the nearest inhabited land. When it was 'discovered' by the Dutchman Jacob Roggeveen, on Easter Sunday 1722, it already had people living on it.

Humans had only been on Easter Island since about AD 1000. Nevertheless, that they had reached this remote spot points to humanity's strong centrifugal tendency. Humans were already in Australia a few thousand years after our emergence as a species, and that journey would have required a sea crossing at some point.

This shows that people do not naturally live together at high densities. They are driven, to some extent, to get away from each other. This outward pressure has several aspects:

For a given technology and way of life, a particular land area will support a limited number of people. As population increases, humans find it easier to move to empty land than to develop ways of supporting more people from the same territory.
Living together causes friction and conflict. Some people may bully others or may impose themselves on others in an effort to keep order. At least part of the population finds it preferable to move away, rather than stay and have its freedom curtailed.
While many humans are happy to drift along with what they know, others have a high degree of 'natural curiosity' that makes them want to explore beyond the known, both geographically and in other ways.

It is now fairly clear, based on genetic data, that humans arose in Africa recently, and spread out from there. Modern humans are therefore all quite closely related.

Nevertheless, I disagree in detail with current reconstructions of the peopling of the world (link requires Google Earth; a Google Maps version is here). According to the view presented in the preceding link, while people reached Australia about 40,000 BC, they did not reach North Africa until 20,000 BC, even though they had evolved on the African continent. Furthermore, while people had got half-way down the African coast by 40,000 BC, they supposedly did not reach the southern tip of Africa until 25,000 BC, even though they were in China and Spain by 40,000 BC and in Britain only a couple of thousand years later. Such a pattern makes little sense and rather shows the limitations of the gene-mapping methodology on which this reconstruction is based.

I suggest that, after emerging in central east Africa, the human species spread to and throughout every continent within a few thousand years, say around 40,000 BC. Only the peopling of oceanic archipelagoes that are not connected to the mainland by chains of intervisible islands did not occur until much later, say from about 5000 BC.

(Although mainstream opinion holds that humans did not move into the Americas until after about 15,000 BC, some archaeologists do place the entry into the Americas around 40,000 BC, on the basis of sites that remain controversial.)

I am still researching this issue...

Now we are awake

2007-04-28T21:59:00.000Z

Clive Wearing was a musician who in the 1980s suffered an infection that destroyed his hippocampus, the part of the brain that lays down long-term memories. Thereafter Clive was unable to remember anything beyond a few minutes at a time. He lived in an eternally fleeting present, in his wife's words 'with no past to anchor it and no future to look ahead to'. As if to compensate, he maintained a diary in which he jotted down his thoughts every two or three minutes. The entries in the diary looked something like this:

10.20 Awake at last
10.23 ~~Actually now I am awake~~
10.25 The above is mistaken. I am awake now!
10.28 No, no, no. NOW I am completely awake.
10.31 FINALLY WOKEN UP!!!!
10.33 Now I really am awake.
10.36 AWAKE FOR THE 1ST TIME IN YEARS
Etc. (See C Blakemore The mind machine pp. 55-8)

The human race suffers from a similar kind of amnesia. Each generation believes that it, at last, is awake, and that its parents and all the generations that went before were scarcely conscious.

This is what lies behind the belief that, until very recently, change has been minimal and only in our era has humanity achieved social and technological take-off. Previous generations are thought to have slumbered their way through lives that showed little variation from start to finish.

In my last post, I quoted a recent writer making this point. Another recent expression of it is the claim of the psychiatrist, R D Laing that "We live in a moment of history where change is so speeded up that we begin to see the present only when it is disappearing".

To show that this attitude is itself a constant of history--just as Clive Wearing constantly believed himself to be waking up--I would like to offer some quotations from earlier writers on the same topic...

Our century has more history in its hundred years than had the whole world in the previous four thousand years; more books have been published in the last century than in the five thousand years before it; for it has profited by the recent inventions of typography, cannon and the marine compass.
-- Tommaso Campanella (1568-1639)
We have raised up a truly philosophical age, in which the deepest recesses of nature are laid open, in which splendid arts, noble aids to convenient living, a supply of innumerable instruments and machines, and even the hidden secrets of our bodies are discovered; not to mention the new light daily thrown upon antiquity.
-- Gottfried Leibniz (1646-1716)
No age hath been more happy in liberty of enquiry than this.
-- Francis Bacon (1561-1626)
Whoever reads these chronicles will find that, from the birth of Christ on, the whole history of the world in these hundreds of years is unparalleled, in every way.
-- Luther (1483-1546, in 1521)

I owe all the above to Pitirim Sorokin in Social and cultural dynamics pp. 272-3. To continue...

[The pace of change today] makes my head giddy.
-- Josiah Wedgwood (1730-95)
What marvellous, stupendous accomplishments human effort has achieved.
-- Augustine of Hippo (354-430)
As for the arts and skills, both those useful for the necessities of life and those created for pleasure, they were either invented or tested by our city [Athens], who then passed them to the rest of the human race to use.
-- Isocrates (436-338 BC)
The discovery of a means to test weights by balances and scales has delivered our life from fraud...Countless numbers of machines also exist...[and] are at hand every day: mills, blacksmiths' bellows, wagons, two-wheeled vehicles, turning lathes, and other things...
-- Vitruvius (1st century AD)

Human achievements

2007-04-23T19:37:00.000Z

It is usual to think of human development as being very slow until recently, when it suddenly took off. Here is a typical quote, from the British sociologist Anthony Giddens, relying on the American political scientist John H Kautsky:

...it is the 'relatively overwhelming absence of major social and economic
change' that characterizes the variant forms of society that existed across the
face of world history until some two or three centuries ago.
(Giddens The constitution of society p. 199)

When one thinks of the inventions of the last one or two hundred years--radio, the internal combustion engine, heavier-than-air flight, spaceflight, computers and the internet--it certainly looks as though many dramatic innovations have occurred in a very short time. Compared to the 30,000 years of the upper paleolithic, when people continued to live by hunting and gathering, the twentieth century seems to have been characterised by dizzying change.

One can also predict this on theoretical grounds. The more people on the planet, and the more technology there already is, the faster we might expect inventions to come.

Yet how should we measure the significance of an invention?

Which was more revolutionary: the invention of the typewriter or the invention of writing? There is a case for saying that the change from a world without writing to a world with writing was more fundamental than the mere technical improvement represented by the typewriter. The word processor is another (impressive) improvement within a long list of improvements affecting writing, such as paper, ink and moveable type, but neither it nor any of these is as revolutionary in its implications as the invention of literacy itself. The word processor is a great boon, but it is just a better way of producing letters and reports. It has not transformed society that much, if we remember that people still managed to organise such things as the Normandy landings or the Apollo programme without it.

The internet, too, could be seen as just another incremental improvement in information technology, building on the original invention of writing. In other words, in this important area of life, the really dramatic change occurred some five thousand years ago. Everything since has been by way of refinement only.

The invention of writing was revolutionary. Everything since can be seen as a technical improvement in the ability to prepare and disseminate written information.

In ancient times, people were already writing letters and books. Through letters, people could carry on conversations when they were physically separated. Through books, people became exposed to ideas and participated in a far-flung intellectual community. What are email and the world wide web but just better ways of achieving the same thing?

All we are seeing today are the latest twists in a long process of getting more information, more quickly to more people. Ever since the invention of writing, there has been almost continual improvement, both technological and institutional. For instance, communications could be improved by better transport or cheaper writing materials, and these could result from technical innovations as well as from the efforts of politicians and entrepreneurs in setting up factories and commercial networks. To give a couple of examples:

In Roman times, communications were improved not only by the building of roads but by the cursus publicus (public mail), which was initially set up for governmental purposes but was also used by private persons. A system of relay stations, where horses were changed, allowed mail to be carried over hundreds of miles at the rate of a horse's gallop.
In eighteenth century Britain, communications improved as tarmac and sprung carriages enhanced the speed and ease of road transport. A network of stage coaches was set up, distributing mail throughout the country.

One might also mention things like the postage stamp and the fountain pen, as well as the continuous evolution of printing since the days of Gutenburg and Caxton. A list of all the inventions and improvements that have advanced information technology would be enormous and would show that in every period, not just in recent times, people might have perceived themselves to be living amidst great changes.

An effect of the internet has been a 'democratisation' of information flow. Blogging allows anyone to publish their opinions, and through blogs we are exposed to alternative narratives beyond those of the 'mainstream media'. We need not believe everything we read, but sceptical commentary ('conspiracy theory') surrounding events such as 9/11 alerts us to possibilities that mainstream channels might wish to conceal. We can take a more intelligent view of what we are being told and it is seemingly harder for the authorities to deceive and control their populations. This feels like a revolutionary social change, but such democratisation has always been an accompaniment of improving information technology. It is said that the introduction of printing loosened the hold of the church over what was published, and helped stimulate the Christian Reformation. The first newspapers and journals in the eighteenth century would have seemed as excitingly subversive as blogs do today, and like blogging they were made possible by technological improvements, in this case to do with better printing presses and the distribution networks created by the stagecoach.

If we think of truly revolutionary inventions--those that are not just an improvement to an existing technique but stand themselves at the beginning of a long process of improvement--they might be more evenly distributed throughout history than we appreciate. Things like agriculture and metal-working were enormously transforming in their day, and unleashed tremendous potential for the future progress of the human race. How can we seriously think of the first generations to farm the land or to cast bronze and still agree with the above quotation that 'social and economic change' was 'overwhelmingly absent' until recent times.

Revolutionary, transforming innovations have occurred throughout history, and the more recent innovations are not necessarily more significant than those of the past.

If things that initially seem revolutionary like word processing and printing can be seen as incremental improvements, then what seem to us like small changes in, say, the design of stone tools might have seemed quite revolutionary when they were made. To us stone tools are just stone tools, but to people who knew nothing else subtle variations would have been important, and perhaps made as much difference to their way of life as the move from typewriters to word processing has made to the task of running a business today. In the same way, what seem to us like big changes, such as the introduction of the internal combustion engine, may seem like trivial improvements to people in the far future--yes, we have dispensed with the horse but otherwise we are still crudely travelling around in four-wheeled vehicles along streets and roads on the planet's surface. When people are zipping from galaxy to galaxy by some form of matter transportation, the difference between a motor-car and a horse-and-cart will not seem that great.

Those fundamental inventions that were made long ago, such as farming, writing and metal-working, did not come entirely out of the blue (I will deal with this in a later post). Nevertheless, insofar as their inventors had fewer models to go on than inventors do today, their achievement might be seen as all the greater. Something like the sewing needle has barely changed since it was invented 30,000 years ago. It was brought to perfection by people living in paleolithic times, and yet it remains a vital component of our technology (I thank my sister for this example).

I do not want to turn things on their head and argue that it was the stone age people who were the real innovators. What I do want to point out is that innovation and change have been part of human experience from the beginning, and the idea that things have dramatically sped up in our own time is a matter of subjective perception as much as objective fact.

Periodisation and orientation

2007-04-22T17:11:00.000Z

In earlier posts, I talked about the overall history of the human race, from its beginnings forty or fifty thousand years ago to its culmination a million or so years from now. I did this so as to dispel the chronocentrism or distortion that comes from viewing history from our particular vantage point.

Since we represent the greatest level of advancement humanity has yet achieved, we tend to have a conceited view of ourselves and of our importance in history. It is common to talk of things happening in our day as 'unprecedented'. Of course, they are unprecedented, but this is an inevitable consequence of the fact that we live in the present and at the forward edge of time, as every generation has done and must do.

The people who lived two thousand years ago did not think of themselves as the ancient Romans, living in the past. They thought of themselves as the most sophisticated, technologically advanced civilisation that the world had ever seen, and that is what they were. Only now do we see them as part of history.

What we must not forget is that we, and our time, are also part of history, which started a long time ago and will continue a long time after we are gone. Once we were the future; today, for a brief moment, we are the present, where everything seems to be happening; and for the remainder of eternity we will be the past, getting deader and more ancient as time goes on.

History is a continuously unfolding saga, and we are just at the latest point of it.

Now that that point has, I hope, been made, I want to concentrate on the history that has actually happened.

We can begin by thinking in terms of the three ages--stone, bronze and iron--that were defined by the Danish archaeologist, Christian Jürgen Thomsen (1788-1865) and his Swedish pupil J J A Worsaae (1821-85). This scheme is a convenient simplification. There was no sharp transition between the various ages, and they occurred at different times in different parts of the world. People continued using stone tools during the bronze age, and they were already experimenting with iron long before the bronze age was over.

The human species emerged in the middle of an ice age, the Würm glaciation, which had then been going on for 60,000 or 70,000 years. (This was just the latest cold snap within the ice age proper, which started 40 million years ago and became more intense 3 million years ago, with repeated cycles of cooling and warming.)

The emergence of humans marks the beginning of the Upper paleolithic (paleolithic = 'old stone' [age]) . Stone tools were being made before this by sub-human hominids, but hundreds of thousands of years could go by with little change in their sophistication. The Upper paleolithic was characterised by more advanced stone-working, a shorter duration, and a process of continual improvement.

With the end of the ice age, it is conventional to recognise the beginning of a new period, the Mesolithic (middle stone age), some 30,000 years after humans emerged. This was characterised by finer stone blades, or microliths, which included arrowheads. It is mainly relevant to Europe, since Africa and the Middle East were already steaming into the Neolithic. This shows the relative arbitrariness of the division into distinct periods; we could as easily consider it a sub-stage within the paleolithic.

The Neolithic (new stone age), from 8000 BC, corresponds to the introduction of agriculture (until now, people had largely hunted and lived off the land). Cities arose in the Middle East, and, though this was still the 'stone age', copper and gold began to be worked (archaeologists sometimes speak of a separate 'Copper Age' or Chalcolithic).

The Bronze age came in from around 3500 BC, when people began mixing copper with tin or arsenic to produce bronze, this being harder and more useful than pure copper.

Finally, the Iron age came in some time after 1000 BC. In so far as hammers and cutting edges continue to be made of steel (an iron alloy known virtually from the beginning of the iron age), we can regard ourselves as in the iron age to this day.

I return to the point that this periodisation is a matter of convenience, to give us some signposts. We should not imagine that a gong rang and suddenly the stone age turned into the bronze age etc. Rather one thing led to another, and everything grew out of what had gone before. Nor should we imagine that the raw materials--stone, bronze, iron--were the be-all and end-all. It is just that these survive best in the soil and are most noticeable to archaeologists. There was also continuous development in other technologies and in the more intangible social, economic and political institutions.

The terrible coming of iron

2007-04-02T19:26:00.000Z

In an earlier post, I presented history as a straight line of steady, upward growth in human capability. This is true only to a first approximation.

Examining history at the next level of detail reveals occasional dark ages, during which the documentary and archaeological records are meagre. This meagreness would appear to be the result of retrenchment in both government and commerce, whereby people no longer produced the kind of durable remains that would survive to the present.

As well as times of retrenchment, these dark ages were also times of innovation, being associated with major transformations of society.

Take as an example the dark age that affected early civilisations in the eastern end of the mediterranean and south-west Asia, around 1000 BC, and that was linked to the introduction of iron. [See a map of the inter-bronze-iron dark age (c. 1200-700 BC) here, in Google Earth. For a Google Maps version, go here.]

The story went something like this. A series of bronze age societies had taken shape over the preceding millennium and were in relative equilibrium, both internally and in their interactions with each other. The introduction of iron changed the equation, and upset the logic on which these societies were based.

Whereas the ingredients of bronze, copper and tin, are found only in a few places, iron is found practically everywhere. Although iron-working requires a more advanced technology, once the process was developed, it could be adopted by almost anyone. The people who had grown rich and powerful controlling the sources of raw materials and distribution networks for the bronze-based economy, suddenly saw their livelihoods disappear.
Since iron-working did not spread instantaneously, those who adopted it first had a great edge over rivals who were still complacently using bronze. Societies that had been most successful with bronze technology were, if anything, least enthusiastic about making the switch, and their rulers and peoples suddenly lost the dominant position they had enjoyed.

As commercial networks collapsed and previously marginal groups began to assert themselves, people struggled to achieve a new equilibrium, i.e. a new way of life adapted to the availability of iron. It is this upheaval that lies behind the meagreness of the historical record. People stopped building large structures, such as palaces, temples and other monuments; trade dwindled, leaving few artefacts for us to find; and society no longer supported administrators and scholars, the kinds of people who generate written records.

It took up to several hundred years to attain the new equilibrium, but when violence abated and commerce resumed, society had been transformed.

In some respects, iron had a 'democratising' effect, producing a proliferation of small states, in which people were given a say in governing themselves. Being less scarce than bronze, it was also less exclusively directed towards elite consumption, and there emerged a middle class, producing and consuming iron-related goods and services. At the same time, iron allowed some rulers to amass military power and conquer a succession of empires. Slavery, although it had existed before, became widespread and endemic, with a large part of the population reduced to unfree status and traded as a commodity.

The author Jim Bailey has characterised these changes, and the disruption from which they emerged, as 'the terrible coming of iron'. This was also the view of the Greek poet Hesiod (late 8th century BC), who regarded the iron-using world of his time as harsher and more miserable than the preceding era of bronze (with a 'race of heroes' having dominated the centuries of conflict between the two).

To sum up, the political, economic and social institutions that 'worked' for the bronze age were not those that would 'work' for the iron age. The period during which bronze institutions were transformed into iron institutions appears from our perspective as a dark age.

I have given this account of the coming of iron not for its own sake but to illuminate a general principle.

History is not a process of steady upward movement but is characterised by periodic setbacks. These setbacks, rather than being mere interruptions to progress, are necessary and fundamental to the way that progress occurs. I call this the phoenix principle.

I would like to make two further points.

This explanation of the bronze-iron dark age does not mean that technology drives history. It only says that to go from bronze to iron required passage through a dark age. What drove that change is another matter, which we will come to.
As an account of some five centuries of history, the above is highly simplified. The aim is to introduce and illustrate the phoenix principle. Ultimately we are going to need more than the phoenix principle to understand history, but we must learn to walk before we run.

A demonstration of self-organised criticality

2007-04-01T16:18:00.000Z

I do not want to overstress the concept of self-organised criticality (SOC), but it is something I will be returning to from time to time.

The following program shows SOC with an example from Per Bak's How Nature Works. The square at top left is a simulated sandpile. When you press the Step button, a 'sand grain' is added to a random position on the pile. If the height at a given position is 4 grains or more, the height is decreased by 4 and 1 grain is added to each of the neighbouring positions, to the north, east, west and south. If the position is at the edge, the grains 'fall off the side'. The height at a given position is shown by shades of grey, with white for 0 grains and black for 3 grains. A field shows the mean height across the whole sandpile.

At first, grains appear in scattered positions, but eventually the pile has grown to the extent that 'avalanches' can occur, whereby the grains 'toppling' from one position cause other positions to become too high and they topple in turn. A field shows the size of each avalanche, in terms of the number of positions where there is a change in height (minimum 1).

As the simulation proceeds, the number of avalanches of different sizes is recorded and eventually a log-log graph is plotted, i.e. a plot of log(N_S) against log(S), where S is the size of avalanche and N_S the number of avalanches of that size. The tell-tale signature of SOC is that such a graph should give a straight line.

Pressing the Step button repeatedly is time-consuming and labour-intensive. Instead, you can press the Run button, which keeps stepping automatically. To pause the simulation, press the Run button again. After the graph has been plotted, the simulation goes into Pause mode, but you can start it again by pressing the Run button.

A field shows the number of events to collect before plotting the graph. This is initially set to 10,000, but you may change it to any value. If the simulation is in Run mode, changing the value does not take effect until after it has gone back to Pause mode.

I may be improving this program in due course.

Self-organised criticality and uniformitarianism

2007-03-18T13:54:00.001Z

Per Bak, discoverer of self-organised criticality, stated that his researches 'disproved' uniformitarianism. In reality, they confirmed it at a deeper level.

IBM sandpile experiment, demonstrating self-organised criticality

Bak misunderstood uniformitarianism as meaning that change is always gradual. However, the deeper meaning of uniformitarianism is that extraordinary effects do not have to have extraordinary causes.

In his famous sandpile experiment, Bak showed that a uniform input (sand falling onto a pile one grain at a time) could produce effects (avalanches of sand falling off the pile) on all scales. Small slippages occurred frequently, medium slippages less often, and large slippages very rarely (once the pile had 'self-organised' to the 'critical' state, that is). Contrary to Bak's view, this is a validation of the uniformitarian principle since it shows that large and unusual phenomena (big avalanches) can arise from the same processes as produce ordinary ones (the continual small avalanches).

Self-organised criticality shows how something like the extinction of the dinosaurs or the fall of the Roman empire need not require some special factor such as a meteorite impact or a barbarian invasion. It may come about through the same processes as lie behind smaller effects, such as the extinction of individual species or everyday fluctations in people's political and economic fortunes.

As used on this website, uniformitarianism means precisely this. History, despite its enormous variety, is to be understood not as a series of chance events with ad hoc causes, but as the expression of eternal and constant principles.

From stone age hunters to masters of the universe

2007-03-18T10:07:00.001Z

To our far distant descendants, we humans who are alive today will seem to have progressed very little beyond the stone age. When people are travelling between the stars and to other galaxies, all the time that we have spent confined to earth will be lumped together as the first, primitive phase of human existence. For an estimate of the timescales, see the following diagram, and the notes below.

The graph is based on the Kardashev scale, as a way of characterising the growth of human capability.

Kardashev level	Refers to a civilisation controlling the resources of an entire...
1	Planet
2	Solar system
3	Galaxy
4	Universe (see note)

(Note. Some define K=4 as controlling a galactic supercluster, with K=5 for the universe. However, I see the step from galaxy to galactic cluster as less of a leap than that from star to galaxy, and not worthy of being denoted by a separate Kardashev level. Whereas routine travel around the solar system is conceivable within the currently understood laws of physics, routine travel around the galaxy would take thousands of years even at the speed of light, which is currently considered impassable. We therefore need new physics to conquer the galaxy in a meaningful sense. However, once we can move around easily within the galaxy, it would not be such a stretch to move to other galaxies, and no more new physics is required. Intra-galactic and inter-galactic travel seem to belong to the same level of human capability.)

Reaching K=4 can be considered to imply some sort of crisis or goal-achievement, in that there can be nowhere to go after mastery of the universe itself. Below, I expressed this in terms of a face-to-face encounter with God and ultimate understanding of reality. Some suggest that we might move into parallel universes, and they envisage another Kardashev level involving the control of the multiverse. However, I suspect we cannot pass from universe to multiverse without 'encountering God' (finding answers to the questions of creation and existence). It is nevertheless possible that this will occur a little bit beyond what we, with our limited knowledge, currently understand as the limits of the universe, i.e. not at K=4 but somewhere beyond K=4.

The pertinent questions are (1) where are we now on the Kardashev scale and (2) how long will it take us to reach K=4 (or a bit more) and mastery of the universe?

Kardashev defined his levels in terms of power consumption (i.e. K=1 means consuming all the power on the planet, K=2 means consuming all the power output by the star etc.). On this basis, humanity is currently at about K=0.7. Assuming a historically realistic rate of energy growth, Kardashev predicted achievement of K=3 in about 5000 years.

This viewpoint can, however, be seen as too historically specific, since the trend Kardashev relied on was only a couple of centuries old and is already faltering. (See the diagram below, where Btoe="billion tons oil equivalent"; data supplied by BP.) Raw energy consumption may have seemed like an important factor from the perspective of the twentieth century, but in the distant past and in the distant future, changes in human capability should probably be measured by other means.

Given that it is barely a hundred years since the Wright brothers, while we now go into space as a matter of course, it may seem reasonable that humans will have made incredible progress and could well be flitting around the galaxy after another few thousand years. However, recent progress may be just a blip. Since the human race has taken something like 50 ky (kiloyears) to reach K=0.7, I think it unrealistic to suppose we could go from K=0.7 to K=4+ in only 5-10 ky.

If the time taken to reach a given civilisational level is proportional to the K value, we might predict achievement of K=4 at about 300 ky, i.e. 250 ky from now. (Using T to represent the time elapsed since the birth of the human race, if T~K, and T=50 ky when K=0.7, we have T_K=4 = 50 x 4/0.7 = (approx.) 300 ky when K=4.)

I believe that even this is an underestimate, however. Considering 50 ky have gone by and we are still only tentatively clawing our way off our planet's surface, we hardly seem likely to have conquered the inconceivably vast universe in just another 250 ky. I imagine that we should be thinking in terms of a million, perhaps several million, years before we achieve ultimate understanding and mastery of the cosmos.

I will defer my detailed reasoning to a later post, but I suggest we assume a relation of the form log(T) = const + K, where T = time elapsed since human speciation and K = Kardashev number. Taking our current value of K as 0.7, I obtain the graph shown at the top of this post. Note that in this graph, the vertical (K) axis is anti-logarithmic, so that, for example, the gap between K=3 and K=4 is bigger than that between K=1 and K=2. Although the graph only goes down to K=0, I envisage a series of negative Kardashev levels before that, where say K=0 represents control of a region, K=-1 represents control of a sub-region etc. At the birth of the human species, we had K=-infinity.

One implication is that the rate of increase of the Kardashev level was faster in earlier times than it is now, and faster now than it will be in future. This might seem counter-intuitive. We normally imagine that progress is speeding up. The explanation is that the size of the problem in moving to the next Kardashev level gets bigger at an even faster rate.

Think in terms of the spread of humanity. Humans had spread across most of the planet at a very early date; the colonisation of Australia is put at about 40,000 BC, i.e. after just 10 ky. At that rate, humans might have thought they would soon be spreading into outer space. However, it has actually taken tens of thousands of years to get ready to leave the planet's surface, despite many attempts at flying machines over the technology for traversing interstellar space is inconceivably harder to develop and detains us for a long time. Remember that, just as early people had no understanding of the science behind space travel, we currently have no understanding of what science might allow travel to the stars (we think it is impossible).

Or look at it another way. Control of a particular Kardashev level becomes harder as we move towards it. Early humans, having occupied most of the planet within 20 ky of speciation, might have thought they were well on the way to K=1. Yet they did not know about farming, metalworking, radio waves or many other technologies we have had to master in order to come close to controlling the planet's resources. Conquest of the solar system or the galaxy may look 'easy', but there are probably issues to overcome we have not yet even dreamed of.

Finally, think in terms of the marginal contribution of each new technology. If you could wave a magic wand and disinvent, say, the mobile phone, it would not take long for people to reinvent it and get us back to where we are now. But if you waved a magic wand and disinvented, say, writing, civilisation would collapse. It could then take a very long time to recover and rebuild. The earliest discoveries, which we take for granted, were the most fundamental and, in Kardashev terms, made a much bigger contribution than do the latest gadgets.

For all these reasons, I think it is fair to suppose that the pace of movement through the Kardashev levels will slow down, and our cosmic quest will take a million or so years to fulfil, not a few thousand.

Birth of the human race

2007-03-17T22:33:00.000Z

I put the birth of the modern human species, Homo sapiens sapiens, at about 50,000 years ago. Around that time, there seems to have occurred a quantum change in social evolution. Beforehand, a hundred thousand years could go by without any noticeable change in the form and technique of stone tools. Afterwards, there was a process of continual development, from stone tools to the Saturn V.

I ascribe this change to the emergence of proper language. No doubt, for a million or more years, the genus Homo had had language skills somewhere between that of modern humans and what chimpanzees have been able to achieve. However, I equate the appearance of 'full' language, implying subtle gradations of syntax and the ability to express any concept, with the achievement of full humanity. Having said this, the crucial innovation was probably not in language per se, but in some more abstract cognitive skill, such as symbolic thought. For instance, a clear distinction between our species and the closely related Neanderthals was that the Neanderthals produced little or nothing that can be called art, whereas early humans were already producing art that stands comparison with modern work. The newly acquired capacities for both art and true language might therefore be traceable back to some novel mental aptitude, common to both.

I admit, such an attempt to pin down the reason for and birthdate of modern humanity is to some extent prejudice and guesswork. There will always be archaeologists pushing back the date of human origins. Nevertheless, one has to have some kind of baseline, and the 40,000 BC date for the emergence of our species is a traditional one in the literature. In speaking of 50,000 years of human existence, I am rounding up this traditional figure in anticipation of future discoveries.

Uniformitarianism and the principle of mediocrity

2007-03-17T22:11:00.000Z

Two philosophical underpinnings of the theory of history and society presented here are uniformitarianism and the principle of mediocrity. Uniformitarianism means attempting to explain apparently disparate phenomena in terms of uniform causes, while the principle of mediocrity means viewing our own position and perspective as normal rather than central.

Charles Lyell is credited with introducing the concept of uniformitarianism in the study of geology. He meant the assumption that the processes we observe today are those that operated in the past. The point was that, rather than imagining special eventualities--such as Noah-like floods, thunderbolts or divine creation--to explain features of the landscape, we should understand them as arising through the normal processes--such as erosion and sedimentation--we can see occurring in front of our eyes. An important consequence, considering the time it would take to erode the Grand Canyon or pile up Mount Everest, was a recognition of the great age of the earth. It is said that Lyell's ideas influenced Charles Darwin, both giving him the idea that species could emerge through slow-acting selection pressures and supplying the vast spans of time that his theory of evolution would need.

Uniformitarianism can be seen as a default assumption of science. Although we have sampled an infinitesimally tiny portion of space, we assume that the laws of physics we observe operating here on our planet also apply everywhere throughout the universe. Astronomers interpret what they see in the heavens by applying familiar principles of science, rather than by postulating novel principles in an ad hoc manner - e.g. explaining the forms of galaxies in terms of gravitational and electro-magnetic forces, rather than in terms of special 'galactic forces'.

Related to this is the principle of mediocrity. It says that we should assume we are in a typical rather than a privileged position with respect to the phenomena we observe. The history of cosmology has been a gradual unveiling of the principle of mediocrity. Early humans thought the earth was at the centre of the universe and that everything revolved around it. Now, not only do we know that the earth is just one of many planets orbiting the sun, but the sun itself has been revealed as an ordinary star in a humdrum part of the Milky Way, which is one of countless similar galaxies spread through the universe.

Neither uniformitarianism nor the principle of mediocrity should be applied in a dogmatic manner. It is rather that they are the most sensible default assumptions, in the absence of evidence to the contrary. In a later post, I will discuss how criticism of uniformitarianism arising from one theory of complex systems reflects a misreading of the concept.

Uniformitarianism does not require rigid insistence that systems' behaviour and properties never change. Astrophysicists entertain the possibility of secular variation in physical laws, and since there are, for example, anomalies in the rotation of galaxies, it is possible that there may be physical laws we have not yet discovered. Nevertheless, the point is that we should seek common explanations that can account for dramatic, large-scale phenomena alongside modest, everyday, local phenomena, before we resort to invoking special, unusual forces. In this respect, it is an example of Ockham's razor.

Similarly, the principle of mediocrity is a point to start from rather than something that must inevitably be true. Suppose you were asked to pick a ball from a bag and it turned out to be blue. It might be that you happened to pick out the single blue ball from a bag full of red balls, but there is no real reason to think that. If you had to predict the colour of a second ball from the same bag, your best bet would be to assume the principle of mediocrity and say blue, even though that is far from guaranteed. This is an artificial situation, but in science the principle of mediocrity is usually a reliable guide.

Applied to the study of history and society these concepts lead to the following assumptions on which the theory is built:

Human beings have been much the same at all times and in all places.
We do not live at a special time in history, nor does our country/society have a special place in the world.

The management of human affairs

2007-03-04T10:01:00.000Z

Some commentators on my 'dark age watch' site described me, in effect, as a fascist. My politics are or should be irrelevant to the observations I offer on these sites, which attempt to be objective statements deriving from a theory of history that is based on study of the past and of historians' writing about it. I do not think of myself as a fascist, because I dislike orthodoxy and I am too insubordinate to belong to any kind of monolithic entity. However, I would be deluded if I claimed to be without bias, and I shall try to explain what views I do hold.

Firstly, I believe in the essential unity of humanity. I do not care too much about the fate of this or that civilisation, including the one I happen to be in. In my view of history, these things are inevitably ephemeral. They serve their purpose for a while, but then it is right that they should go. What is important, I would say, is the future of the human race, to which we all belong.

Secondly, I believe in freedom ahead of equality, and in less government not more. Freedom and equality are incompatible. If people are to be allowed to realise their potential, they will end up unequal, since all have different aptitudes and abilities. If people are to be made equal, there must be an element of compulsion and control over their behaviour. Small government means people being free to achieve; big government is needed to impose and enforce equality. Nevertheless, the situation is not black and white. Some might speak of equality of opportunity versus equality of outcome, where you can have one or the other but not both. Yet take education. Providing free schools is creating equality of opportunity from the perspective of the individual child, but from the perspective of the family or parents it creates equal outcomes, i.e. schooling their children regardless of their own efforts. Equality of opportunity can therefore sometimes require equality of outcome. Unbridled freedom and laissez faire may mean wasting human potential. (Even with free schooling, as Bourdieu argued, education tends to project the values and reproduce the power relations of the existing, unequal social order, so that further interventions may be justified.) Meanwhile, the society that does not assist and support its weaker members not only would be inhuman but is historically very rare. A balance has to be struck. This balance between freedom and equality can only be negotiated through a political process. All I am saying is that my bias is towards the freedom side, or that, other things being constant, I feel a lack of freedom to be less 'fair' than a lack of equality. This perhaps makes me right-wing.

Thirdly, I do not believe that what we call democracy is a good form of government. I am fond of saying, usually after a few drinks, "the universal franchise has been an absolute disaster for this country". Democracy allows power to be obtained by the people who should not have it, while elected politicans tend to bribe the voters with ever-increasing subsidies. Such here-today-gone-tomorrow rulers find it hard to act for the long term, since that requires sacrifice and sustained commitment. By contrast, hereditary rulers, who "own" the societies they govern, treat them thoughtfully. Furthermore, their temperaments are not exclusively those of power-seekers but reflect the full range of human personalities, and, since they do not have to manoeuvre their way to the top, they have no reason to act corruptly. It might be thought that such political forms are unfair, holding back talent, and denying opportunity, but there is always social mobility, and people can participate in power as advisers and agents of the rulers. Again, the situation is not black and white, and a balance must be struck. Absolute despots often destroy their societies (as do democracies though), and it is perhaps best when the monarch rules in conjunction with some form of representative assembly. I would nevertheless commend traditional and hereditary methods of choosing the representatives, rather than any widespread franchise. This might make me an authoritarian.

Fourthly, I reject "environmentalism" along with concerns about overpopulation or running out of natural resources. Environmentalists see humans as a contaminant within the universe, using too much energy and creating too much pollution. I disagree. For me, nothing in the universe has meaning except as it relates to humans and our struggle to find out who we are and why we are here. We are supposed to exploit the universe's resources in pursuing our mysterious quest. I do not worry about exhausting such resources because I consider our stay on this planet to be a brief, initial phase, soon coming to an end. What this universe does not lack are energy, raw materials and room to contain expanding human numbers. As we move out to other planets and later other star systems, concerns about global warming will come to seem utterly irrelevant. It is just that necessity is the mother of invention, and population, resource and environmental stresses are the incentives we need to get off the planet.

These are some of my views. I do not claim that they are consistent, have been well thought through, or add up to any kind of manifesto. It is not my purpose to take up political positions. On the whole, I view the antics of the human race not entirely favourably, yet I cannot help but smile all the same.

Coming of age in the cosmos

2007-03-03T18:21:00.000Z

Humans are not destined to remain forever on this tiny planet we now inhabit. The earth is just our birthplace. In terms of a computer game, the terrestrial phase of our existence is Level 1. We are supposed to get out there into the universe, where many remarkable discoveries await us. We cannot answer the deeper mysteries of existence by sitting in this obscure backwater. Out there, in the fullness of time, we will find answers to all humanity's questions. I take seriously the Fermi paradox and the anthropic principle, in that I believe humans are alone in the universe, which has been set as a puzzle for us to solve. The following cartoon explains my vision of the long-term adventure of the human race. (Click to expand the pictures, or click on the title above for a PDF version.)

One great city

2007-03-03T15:44:00.001Z

The world is one great city, and the substance out of which it is formed is single, and there must necessarily be a cycle of change, in which one thing gives way to another, and some things are destroyed and others come into being, and some things remain where they are and others are moved. (Epictetus, ex-slave and Stoic philosopher, 1st century AD)

Things beyond

2007-02-28T22:23:00.000Z

Proposing as I do to speak of the spiritual as well as the material affairs of the human race, I would like to begin by explaining what I myself believe.

Firstly, I believe in God, the Cosmic Forces, call them what you will. I believe in God through being aware of God. I cannot not believe in God. People who confidently dismiss God, faith and spiritual experience as primitive superstition long disproven by science seem to me not to have understood the question. As Kenneth Boulding once put it: we know nothing about the creation of thermodynamic potential. There remain great mysteries of existence and consciousness, and it is premature to claim that the universe is only what we immediately perceive it to be and nothing more. Proving that religion is flawed and man-made, and that holy scriptures are a farrago of self-contradictory materials, is old hat, and says nothing about the questions that these were inadequate attempts to address.

Secondly, I believe that God (a term of convenience) answers our prayers, though only those we offer on our own behalf. This may seem to imply that God is in favour of selfishness, but the point is that we must each conduct our own relationship with God; others cannot do it for us. For prayer to be effective, we must have faith, genuinely want what we are asking for and believe God will help us (we usually only get into that frame of mind when truly in despair). These views are based on my personal experience. There have been experiments seemingly showing that intercessory prayer (praying for others) is valueless or even harmful. While this supports my view, the experiments are nonsensical, being based on the fallacy that God is a material phenomenon discoverable through the methods of science. Putting God to an empirical test hardly suggests the level of sincerity that prayer needs. Meanwhile, some might say that there is a rational explanation for the efficacy of praying for yourself, in that it creates a positive frame of mind. Maybe so, but the point remains: prayer works.

Thirdly, I believe that we survive death in some way or other, though there are problems about this that trouble me. One problem is what aspects of us survive. For example, what about psychopaths, or intelligence versus stupidity - do such traits persist? The idea seems intolerable. Buddhists say that these traits are part of an outer personality that is shed and it is an inner essence that survives. This may be the answer, but I still have a problem thinking about say mass murderers floating around in some spiritual dimension on a par with their victims - unless you believe in hell, but then there are questions about responsibility: how far can someone born stupid or psychopathic be blamed for their actions? The other main problem is that our awareness/consciousness/existence disappears every night during certain phases of sleep. Why should it not also disappear at death, when the brain shuts down entirely? I have no answers here. If we do survive death, perhaps all will be revealed and make sense then. These gospel lyrics help me think about death.

Fourthly, I consider myself a trinitarian Christian. This is in the sense that I believe the doctrine of the trinity (God in Three Persons) to express an important spiritual truth. To quote Roger Jones (basing himself on Marie-Louise von Franz), "One is the symbol of the ultimate unity, the unus mundus, the primal fount of all things. Two is duality, the first mysterious splitting of oneness into distinguishable parts, that incomprehensible articulation which symbolizes the very process of creating an extended differentiable universe out of the primal chaos. Three is the tension between one and two, the dynamic actualization of the psychic and physical realms. Three is manifestation...But three is also the trinity, the synthesis of one and two, and thus the symbolic return to unity." These ideas can be traced back to the ancient Egyptians, whose creation myths speak of 'the One' who then 'regards himself', generating the two opposites, which then collide to produce in their synthesis and reunification the third element: "It is I who spat out Shu, I who expectorated Tefnut. I had come into being as One God and behold there were Three." (citations from the exposition of Lucie Lamy). These ideas are messier than the pure simplicity of Islamic monism, but not as involved as the Hindu pantheon (nevertheless, trinitarian ideas can be found in both Islam and Hinduism). I do not discount cultural factors in predisposing me to believe them. Meanwhile, I understand Christ as more than a person who lived at a particular point in time. I believe in the divinity of Christ, which places Christ outside time. Christ always was, and embodies a permanent, transcendent mystery, which is that of dying and resurrection, destruction and renewal, life out of death. This is the principle of creative destruction that we see in the biological, psychological and social realms: the old must disappear so that the new can come into being. In my theory of history, I call it the phoenix principle.

This is what I believe. I do not say all this because I think you should agree with me, or even approve of what I say. It is so that you can understand what kind of person you are dealing with.

t	= total time resource to produce artefact ( ≡ technological sophistication)
t_m	= time resource for actually making the artefact
t_p	= time resource for preparation
t_s	= time resource for skill acquisition
t_i	= total time resource to produce input i ( ≡ technological sophistication of input i)

Relationship	Intimacy	Trust
Friendship	Yes	Yes
Acquaintanceship	No	Yes
Strangership	No	No