Saturday, November 19, 2005

Genes and Civilisation   posted by DavidB @ 11/19/2005 12:42:00 AM

[Added: using some browsers you may see some odd symbols in the following. These should be single quote marks.]

In a previous post on interracial marriage I suggested:

It is conceivable...that the distinctive achievements of European culture have depended on the prevalence of certain combinations of intelligence and personality which in turn depended on gene-combinations that are more common among Europeans than elsewhere, and which would become rarer if the European gene-pool were to merge with, say, the Chinese gene-pool. I don't know of any serious evidence for this, but I don't think it can be dismissed as absurd.

In comments there was a lot of discussion on this point, so I want to consider it further. The present post will give some reasons for being sceptical about any close link between genes and cultural achievement, while a second post will give reasons for not dismissing it as absurd.

I will not say much about intelligence, because the whole question of population differences in intelligence (as measured by IQ) is complex, and there is no shortage of previous discussion of the subject. I would just point out that on a timescale of millennia, the genetic basis of population IQ differences is not fixed. There are about 30 generations to a millennium, so with even modest selective influences on mean IQ (say, up to half an IQ point per generation), the observed differences between populations (around 15 IQ points plus or minus from the global mean) could be due to comparatively recent changes - by which I mean within the last few millennia, rather than deep in the Palaeolithic.

In any event, there is no reason to suppose that mean genetic IQ differs dramatically within Eurasia, so I will confine my discussion to Europe and Asia, with the obvious extension to people of recent European or Asian descent elsewhere. Within Eurasia, Europe has probably always accounted for a fairly small proportion of total population - less than a quarter - yet seems to have accounted for a very large share of cultural achievements. In his book on Human Accomplishment, for example, Charles Murray concludes that a majority - over 70% - of identifiable cultural achievement throughout the world since 800 BC can be attributed to Europeans or people of European descent.

Of course, Murray's statistics can be criticised. He bases them on biographical dictionaries and other reference works, which to some extent reflect the limited knowledge and interests of the compilers of such works. But it would be difficult to dispute that Europe has accounted for a disproportionate share of achievements in this period.

For the present purpose a more serious objection is that the cultural dominance of Europe depends on the period chosen for study. Europe has only taken the global cultural lead during two periods: from 500 BC to around 300 AD, and from around 1400 AD to the present (counting the USA as an extension of Europe). If a medieval (and probably Islamic) scholar had taken a survey around the year 1000 AD, he would have found China, the Islamic world, and India far more culturally developed than Europe. If we take 'civilisation' as dating back to around 3000 BC, Europe has been culturally dominant for only about a quarter of the time. All the main parts of Eurasia - Europe, the Middle East, South Asia, and the Far East - have at some time achieved high levels of 'civilisation'.

It would therefore be difficult to argue that European dominance is strictly determined by some advantage of the European gene pool. We also find that there have been sharp fluctuations in the relative performance of different countries or regions within Europe, with no obvious genetic basis. For example, in the 17th century Scotland and Switzerland were cultural backwaters, notable only for religious bigotry, but in the 18th century they were head-for-head the most creative places in the world, with such major figures as Hume and Adam Smith in Scotland, or Euler and Rousseau in Switzerland (see Note 1). Rapid changes of this kind should make us sceptical of any simple relationship between genes and 'civilisation'.

It is evident that cultural vitality depends in part on economic and political circumstances. Economic prosperity usually goes together with achievement in the arts and sciences, a striking example being the golden age of the Netherlands in the 17th century. Conversely, it is difficult to think of any case where prolonged economic stagnation or decline has been accompanied by great cultural achievements, though it is not incompatible with artistic charm and sophistication, as in 18th century Venice.

The shifting patterns of economic prosperity themselves are notoriously difficult to explain. Whole libraries of books have been written to explain why the Industrial Revolution occurred first in England, rather than anywhere else, but there is no consensus on the subject. Most explanations involve a combination of a least three or four different factors. It is likely that this applies to economic growth and decline generally.

On a global scale the cultural dominance of Europe since 1400 AD coincides with European economic growth and political expansion relative to other parts of the world. It is tempting to regard European dominance as somehow pre-destined, but it is not difficult to imagine circumstances - for example if the Chinese, rather than the Europeans, had occupied the Americas, or if the Mongols had ravaged Europe in the 13th century - where the balance of advantage would have favoured Asia.

And yet - I still can't help wondering if there is something special about Europe, that can't be explained just by some happy combination of historical and economic circumstances. From time to time - as in Greece in the 5th century BC, or Renaissance Italy - there have been dazzling bursts of creativity that to the best of my knowledge simply can’t be matched in any other region. Perhaps the most striking example is the scientific revolution of the 17th century, sometimes called the 'century of genius'. Simply to list the major figures should inspire awe: Galileo, Kepler, Gilbert, Descartes, Fermat, Torricelli, Pascal, Harvey, Huygens, Boyle, Wren, Hooke, Newton and Leibniz, to mention only some of the most obvious. There are few non-European scientific figures to compare with any one of these, let alone such a cluster within a single century. One of their most striking features - which applies also to other creative periods in Europe - is their intellectual ambition and courage: their willingness to overturn traditional doctrines in pursuit of truth (or personal glory!), even at risk of persecution. This seems to be a matter of personality as much as intellect. Granted that there are social and economic preconditions for such a flowering of creativity, can it be explained purely by environmental circumstances? Or is there also some specific basis in genetics?

In a second post I want to take a further look at the basis for scientific creativity, with a comparison of the history of science in Europe and China.

Note 1: I have counted the Republic of Geneva as part of Switzerland for this purpose, though in the 18th century it was not in the Swiss Confederation. Apart from Euler and Rousseau, other notable C18 Swiss include the Bernoulli family of mathematicians, the biologists Haller, Bonnet and Trembley, and the pioneering geologist H. B. de Saussure. As for Scotland, apart from Hume and Smith, we might mention the philosophers Hutcheson, Reid and Kames, the scientists Black, Watt, and Hutton, the novelist Smollett, the poet Burns, and the historian Robertson. Scotland was far more creative than England in this period, in sharp contrast to the preceding century.