Ron Unz, writing at The American Conservative, adds to the debate on nature vs nurture as a determinant for intelligence. He does this by using data from IQ And The Wealth Of Nations by Richard Lynn and Tatu Vanhanen. In this book, the authors conclude that IQ is largely inherited, and that it is a major factor in the success of nations. Unz uses data from the book to question their conclusions. First, he looks at data from Germany and Greece.
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.
The dreary communist regime of East Germany was certainly far poorer than its western counterpart and its population may indeed have been “culturally deprived” in some sense, but East Germans hardly suffered from severe dietary deficiencies during the 1960s or late 1950s when the group of especially low-scoring children were born and raised. The huge apparent testing gap between the wealthy West and the dingy East raises serious questions about the strict genetic interpretation favored by Lynn and Vanhanen.
Next, consider Greece. Lynn and Vanhanen report two IQ sample results, a score of 88 in 1961 and a score of 95 in 1979. Obviously, a national rise of 7 full points in the Flynn-adjusted IQ of Greeks over just 18 years is an absurdity from the genetic perspective, especially since the earlier set represented children and the latter adults, so the two groups might even be the same individuals tested at different times. Both sample sizes are in the hundreds, not statistically insignificant, and while it is impossible to rule out other factors behind such a large discrepancy in a single country, it is interesting to note that Greek affluence had grown very rapidly during that same period, with the real per capita GDP rising by 170 percent.
Or, we can look at the results in Poland during their economically difficult 1980s.
Two samples of Poles from 1979 and 1989 provided widely divergent mean IQs of 106 and 92, with the low Polish figure of 92 coming from a huge sample of over 4000 children tested with “Progressive Matrices,” supposedly one of the most culturally-independent methods. On the other hand, more economically advanced Communist countries in Central Europe often had considerably higher scores, with the Slovaks testing at 96 in 1983, the Czechs scoring 96–98 in 1979–1983, and the Hungarians reaching 99 in 1979.
Austria and Croatia are neighbors, yet have had wide differences in measured IQ.
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.
Unz notes that the big difference in these areas and times, was economic stability and affluence.
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. For example, Austria had many times Croatia’s per capita GDP during the period in question. One of the few European nations to exhibit a sharp decline in tested IQ, Poland—whose score fell from 106 in 1979 to 92 in 1989—did so amid the economic turmoil of the 1980s, when its per capita GDP also substantially declined according to some measures, even while Western Europe was growing richer.
If these differences were truly genetic, they should persist when citizens of those countries move elsewhere, in particular the U.S. Instead, those differences disappear.
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.
Unz notes the very large differences in IQ measures among US and Israeli Jews.
The Lynn/Vanhanen data on Jews also provide some suspicious IQ disparities. American Jews have among the highest tested IQs, with means being usually reported in the 110–115 range. Yet Lynn and Vanhanen report that Israeli Jews have strikingly low IQs by comparison. One large sample from 1989 put the figure at 90, while a far smaller sample from 1975 indicated an IQ of 97, with both results drawn from Israel’s large Jewish majority rather than its small Arab minority. The IQ gaps with American Jews are enormous, perhaps as large as 25 points, and difficult to explain by genetic factors, since a majority of Israel’s Jewish population in that period consisted of ethnic Askhenazi (European) Jews, just like those in America. The huge economic gulf between Israeli Jews, who then had less than half the average American per capita GDP, and American Jews, who were far above average in American income, would seem to be the most plausible explanation.
I believe that Unz adds considerably to this long running debate. There are too many inconsistencies to make the claim that genetics are the sole contribution to intelligence. He makes a compelling case, as others have, that environmental factors are also a significant factor in determining intelligence, and in some cases it may be the dominant factor. The exact balance remains unknown, and it looks as though we may be dealing with too many factors to determine how intelligence is determined with our available tools. As Unz points out, East Asians appear to have IQ measures that are completely unaffected by environmental or economic differences. Finally, if IQ is important in determining the success of nations as well as individuals, we need to find some explanation to make all of this data fit. Clearly all East Asian countries are not equally successful. European countries with higher than average IQs, are capable of spectacular economic failures.