Standing in sharp contrast to the economists’ working assumption that people the world over are interchangeable units is the idea that national disparities in wealth arise from differences in intelligence. The possibility should not be dismissed out of hand: where individuals are concerned, IQ scores do correlate, on average, with economic success, so it is not unreasonable to inquire if the same might be true of countries.
The global IQ/wealth thesis is connected with the interminable debate about black and white IQ differences in the United States, but it involves somewhat different issues and builds more on that part of the evidence about which both sides agree.
The two camps in the IQ debate are known as hereditarians and environmentalists. Both sides generally agree that when IQ tests are administered in the United States, European Americans score 100 (by definition—their scores are normalized to 100), Asian Americans score 105 and African Americans score 85 to 90. The African American score is noticeably lower than the European score (15 points, or one standard deviation, say the hereditarians; 10 points, say the environmentalists). So much is agreed. The controversy arises in interpreting the gap between the European and African American scores. The hereditarians say the difference in scores is due 50% to environmental reasons and 50% to genetics, although they sometimes change the mix to 20% environment and 80% heredity. The environmentalists assert that the entire gap is due to environmental impediments and that if these were removed, the gap would ultimately disappear altogether.
The heritability of intelligence, the measure which the two sides interpret so differently, does not refer, as easily might be supposed, to the extent to which intelligence is governed by the genes. It refers to the variation in intelligence within a population, and specifically to the extent to which this variation is genetic. A trait could be under complete genetic control, but if there were no variation in the population, its heritability would be zero. Intelligence is almost certainly under genetic influence but none of the responsible alleles has yet been identified with any certainty, probably because each makes too minute a contribution to show up with present methods.
The two sides in the IQ debate are not so terribly far apart on the facts, given that both sides agree that environmental factors are involved. The hereditarians concede that if an adjustment is made for socioeconomic status, with which IQ score is correlated, then African American scores would rise 5 points, to 90. That is not so much greater than the gap that separates Asian Americans from European Americans, about which no one seems to be bothered.
Why, then, is the debate so heated? The acrimony arises because the two positions lead to different policy choices. The hereditarians say that since the IQ gap is substantially innate, the Head Start early education program has failed, as was predicted by Arthur Jensen in 1969, and so will similar interventions. The environmentalists deny this, saying the gap in educational attainment is closing, and that it is the racist nature of society that impedes African American advancement.
That issue needn’t be resolved here. The question of global IQ is a somewhat less fraught issue and is of considerable evolutionary interest because intelligence reflects evolutionary changes in the brain and behavior.
The principal proponents of the global IQ/wealth thesis are Richard Lynn, a psychologist at the University of Ulster, and Tatu Vanhanen, a political scientist at the University of Tampere in Finland. They have gathered data from around the world and worked out the correlation between intelligence, as measured by IQ tests, and various criteria of economic success, such as gross national product per capita. Their findings are published in two books, IQ and the Wealth of Nations (2002) and IQ and Global Inequality (2006).
The world’s average IQ, they report, is 90. Broken down by race, the IQ of East Asian nations is 105, the European score is 99, and sub-Saharan Africa’s is 67.43 The authors note that the sub-Saharan African score would be considerably higher but for malnutrition and ill health.
Lynn and Vanhanen argue that IQ scores must be measuring something significant because IQ correlates well with measures of educational attainment. The scores are indeed strongly associated, they say, with what economists call human capital, which includes training and education.
Turning to economic indicators, they find that national IQ scores have an extremely high correlation (83%) with economic growth per capita and also associate strongly with the rate of economic growth between 1950 and 1990 (64% correlation).44
“Our argument is that differences in the average mental abilities of populations measured by national IQ provides the most powerful, although not complete, theoretical and empirical explanation for many types of inequalities in human conditions,” Lynn and Vanhanen conclude.45 It follows from this conclusion that not much can be done to reduce inequities in national wealth. “The gap between rich and poor countries can be expected to persist as far as it corresponds to differences in national IQs,” they say.46
It may seem intuitively plausible that a more intelligent population might garner more wealth than a less intelligent one. But intelligence is a quality of individuals, not of societies. A society of strong men might easily be defeated by weaker men if the weaklings are more cohesive and fight harder. Like strength, the property of individual intelligence does not necessarily transfer from individuals to the society of which they are par
And indeed with Lynn and Vanhanen’s correlations, it is hard to know which way the arrow of causality may be pointing, whether higher IQ makes a nation wealthier or whether a wealthier nation enables its citizens to do better on IQ tests. The writer Roy Unz has pointed out from Lynn and Vanhanen’s own data examples in which IQ scores increase 10 or more points in a generation when a population becomes richer, showing clearly that wealth can raise IQ scores significantly. East German children averaged 90 in 1967 but 99 in 1984. In West Germany, which has essentially the same population, averages range from 99 to 107. This 17 point range in the German population, from 90 to 107, was evidently caused by the alleviation of poverty, not genetics.
There is a 10 to 15 point difference in IQ scores between the richer and poorer countries of Europe, yet these differences disappear when the inhabitants migrate to the United States, so the differences are evidently an environmental effect, not a genetic one. If European IQ scores can vary so widely across different decades and locations, it is hard to be sure that any other ethnic differences are innate rather than environmental. Lynn and Vanhanen’s book “constituted a game-ending own-goal against their IQ-determinist side,” Unz concluded, but “neither of the competing ideological teams ever noticed.”
Lynn and Vanhanen do in fact acknowledge the role of wealth in enhancing IQ scores. But the difficulty of quantifying the IQ-enhancing effect of wealth seriously weakens the ability of IQ scores to explain wealth. More generally, it may be hazardous to compare the IQ scores of different races if allowance is not made for differences in wealth, nutrition and other factors that influence IQ.
East Asia is a vast counterexample to the Lynn/Vanhanen thesis. The populations of China, Japan and Korea have consistently higher IQs than those of Europe and the United States, but their societies, despite their many virtues, are not obviously more successful than those of Europe and its outposts. Intelligence can’t hurt, but it doesn’t seem a clear arbiter of a population’s economic success. What is it then that determines the wealth or poverty of nations