[H]e singled out IQ and the Wealth of Nations, published in 2001 by Richard Lynn and Tatu Vanhanen, as a particularly extreme and hateful example of this trend. These authors explicitly argue that IQ scores for different populations are largely fixed and hereditary, and that these—rather than economic or governmental structures—tend to determine the long-term wealth of a given country. (...)
Although “intelligence” may be difficult to define precisely, most people have accepted that IQ scores seem to constitute a rough and measurable proxy for this trait, so Lynn and Vanhanen have collected a vast number of national IQ scores from the last 50 or 60 years and compared these to income levels and economic growth rates. Since experts have discovered that nominal IQ scores over the last century or so have tended to rise at a seemingly constant rate—the so-called “Flynn Effect”—the authors adjusted their raw scores accordingly. Having done so, they found a strong correlation of around 0.50–0.75 between the Flynn-adjusted IQ of a nation’s population and its real per capita GDP over the last few decades, seemingly indicating that smarter peoples tend to be wealthier and more successful.
From this statistical fact, Lynn and Vanhanen draw the conclusion that intelligence leads to economic success and—since they argue that intelligence itself is largely innate and genetic—that the relative development ranking of the long list of nations they analyze is unlikely to change much over time, nor will the economic standing of the various groups within ethnically mixed countries, including the United States.
Now this hypothesis might indeed be correct, but it is not necessarily warranted by the empirical data that Lynn and Vanhanen have gathered. After all, if high national IQ scores are correlated with economic success, perhaps the high IQs cause the success, but it seems just as possible that the success might be driving the high IQs, or that both might be due to some third factor. Correlation does not imply causality, let alone the particular direction of the causal arrow. A traditional liberal model positing that socio-economic factors strongly influence performance on academic ability tests would predict exactly the same distribution of international results found by Lynn and Vanhanen. (...)
[L]et us restrict our initial examination to the 60-odd IQ datapoints Lynn and Vanhanen obtained from European countries and their overseas offshoots over the last half-century. Obviously, some of these countries have at times been far poorer than others, but almost none have suffered the extreme poverty found in much of the Third World.
What we immediately notice is a long list of enormous variations in the tested IQs of genetically indistinguishable European peoples across temporal, geographical, and political lines, variations so large as to raise severe doubts about the strongly genetic-deterministic model of IQ favored by Lynn and Vanhanen and perhaps also quietly held by many others. (Unless otherwise indicated, all the IQ data that follow are drawn from their work and incorporate their Flynn adjustments.)
Consider, for example, the results from Germany obtained prior to its 1991 reunification. Lynn and Vanhanen present four separate IQ studies from the former West Germany, all quite sizable, which indicate mean IQs in the range 99–107, with the oldest 1970 sample providing the low end of that range. Meanwhile, a 1967 sample of East German children produced a score of just 90, while two later East German studies in 1978 and 1984 came in at 97–99, much closer to the West German numbers.
These results seem anomalous from the perspective of strong genetic determinism for IQ. To a very good approximation, East Germans and West Germans are genetically indistinguishable, and an IQ gap as wide as 17 points between the two groups seems inexplicable, while the recorded rise in East German scores of 7–9 points in just half a generation seems even more difficult to explain. (...)
During this same period, the far richer non-Communist nations of Europe—such as Austria, Britain, the Netherlands, Belgium, Norway, and West Germany—all tended to score at or somewhat above 100. The wide IQ gaps between these European peoples and the previous group seem unlikely to have a heavily innate basis, given the considerable genetic and phenotypic similarity across these populations. For example, the borders of Austria and Croatia are just a couple of dozen miles apart, both are Catholic countries that spent centuries as part of the Austro-Hungarian Empire, and it is quite difficult to distinguish Austrians from Croatians either by appearance or by genetic testing. Yet the gap between their reported IQ scores—12 points—is nearly as wide as that separating American blacks and whites.
It seems more plausible that most of the large and consistent IQ gaps between Western Europeans and their Balkan cousins are less a cause than a consequence of differences in development and affluence during the era in which these IQs were tested. (...)
If these differences of perhaps 10 or even 15 IQ points between impoverished Balkan Europeans and wealthy Western ones reflected deeply hereditary rather than transitory environmental influences, they surely would have maintained themselves when these groups immigrated to the United States. But there is no evidence of this. As it happens, Americans of Greek and South Slav origins are considerably above most other American whites in both family income and educational level. Since the overwhelming majority of the latter trace their ancestry to Britain and other high IQ countries of Western Europe, this would seem a strange result if the Balkan peoples truly did suffer from an innate ability deficit approaching a full standard deviation.
Similar sharp differences occur in the case of Italian populations separated historically and geographically. Today, Italian-Americans are very close to the national white average in income and education, and the limited data we have seem to put their IQ close to this average as well. This would appear consistent with the IQ figures reported for Italy by Lynn and Vanhanen, which are based on large samples and come in at just above 100. However, there is a notoriously wide economic gap between northern Italy and the south, including Sicily. The overwhelming majority of Italian-Americans trace their ancestry to the latter, quite impoverished regions, and in 2010 Lynn reported new research indicating that the present-day IQ of Italians living in those areas was as low as 89, a figure that places them almost a full standard deviation below either their Northern Italian compatriots or their separated American cousins. Although Lynn attributed this large deficit in Southern Italian IQ to substantial North African or Near Eastern genetic admixture, poverty and cultural deprivation seem more likely explanations. (...)
Similarly, a large 1990 test of South African whites placed their IQ at 94, considerably below that of the Dutch or English peoples from whom they derive, and again this may be connected to their lower level of national income and technological advancement.
Perhaps the strongest evidence supporting this cultural rather than genetic hypothesis comes from the northwestern corner of Europe, namely Celtic Ireland. When the early waves of Catholic Irish immigrants reached America near the middle of the 19th century, they were widely seen as particularly ignorant and uncouth and aroused much hostility from commentators of the era, some of whom suggested that they might be innately deficient in both character and intelligence. But they advanced economically at a reasonable pace, and within less than a century had become wealthier and better educated than the average white American, including those of “old stock” ancestry. The evidence today is that the tested IQ of the typical Irish-American—to the extent it can be distinguished—is somewhat above the national white American average of around 100 and also above that of most German-Americans, who arrived around the same time.
Uma coisa que sempre achei duvidosa nas tais teorias que dizem que o povo A ou B são mais desenvolvidos por serem geneticamente mais inteligentes é como é que eles explicam as viariações que ao longo dos séculos houve entre a hiearquia de desenvolvimento entre diferentes países e regiões - afinal, o Iraque, o Egito e a Grécia já foram dos países mais desenvolvidos do mundo (e os autores gregos e latinos por vezes escreviam textos descrevendo os germanos e celtas - as supostas "raças superiores" dos autores dos séculos XIX e XX - como "raças primitivas"); mesmo que invasões e migrações tenham alterado alguma composição étnica dos habitantes desses territórios, duvido que as qualidades genéticas das suas populações actuais sejam muito diferentes do que na Antiguidade (até porque muitas das invasões foram por povos vizinhos e aparentados, supostamente geneticamente semelhantes).