My university doesn’t subscribe to the journal, but I’d really be interested in reading this paper by Satoshi Kanazawa of the London School of Economics. Even better would be if someone else would critique it so I wouldn’t have to waste my time on it.

Mind the gap…in intelligence: Re-examining the relationship between inequality and health.

Kanazawa S.
Interdisciplinary Institute of Management, London School of Economics and Political Science, UK.

Wilkinson contends that economic inequality reduces the health and life expectancy of the whole population but his argument does not make sense within its own evolutionary framework. Recent evolutionary psychological theory suggests that the human brain, adapted to the ancestral environment, has difficulty comprehending and dealing with entities and situations that did not exist in the ancestral environment and that general intelligence evolved as a domain-specific adaptation to solve evolutionarily novel problems. Since most dangers to health in the contemporary society are evolutionarily novel, it follows that more intelligent individuals are better able to recognize and deal with such dangers and live longer. Consistent with the theory, the macro-level analyses show that income inequality and economic development have no effect on life expectancy at birth, infant mortality and age-specific mortality net of average intelligence quotient (IQ) in 126 countries. They also show that an average IQ has a very large and significant effect on population health but not in the evolutionarily familiar sub-Saharan Africa. At the micro level, the General Social Survey data show that, while both income and intelligence have independent positive effects on self-reported health, intelligence has a stronger effect than income. The data collectively suggest that individuals in wealthier and more egalitarian societies live longer and stay healthier, not because they are wealthier or more egalitarian but because they are more intelligent.

What brings it up is that a reader sent me a link to a Guardian article on the subject of this paper, and I find it hard to believe that it actually makes such strong causal claims…even though the abstract does plainly state that the author is arguing for a causal relationship between intelligence and poverty, and it’s not in the direction I would think reasonable.

The London School of Economics is embroiled in a row over academic freedom after one of its lecturers published a paper alleging that African states were poor and suffered chronic ill-health because their populations were less intelligent than people in richer countries.

Satoshi Kanazawa, an evolutionary psychologist, is now accused of reviving the politics of eugenics by publishing the research which concludes that low IQ levels, rather than poverty and disease, are the reason why life expectancy is low and infant mortality high. His paper, published in the British Journal of Health Psychology, compares IQ scores with indicators of ill health in 126 countries and claims that nations at the top of the ill health league also have the lowest intelligence ratings.

You know, I could believe that the populations of nations ravaged by disease, poverty, and war would test poorly. I am not surprised that people could develop tests in the Western world, rush into a completely different culture (not to mention one distracted by serious internal problems), and find that the inhabitants do not respond to their tests with quite the due seriousness they do at home. I do wonder, though, how anyone in their right mind could make this claim:

In the paper he cites Ethiopia’s national IQ of 63, the world’s lowest, and the fact that men and women are only expected to live until their mid-40s as an example of his finding that intelligence is the main determinant of someone’s health.

An IQ of 63 means the average person in Ethiopia is clinically mildly mentally retarded; that’s a result that’s over two standard deviations away from the mean. If you look it up in the DSM-IV, you’ll find that this means they are at best capable of sixth-grade work, and that they are marginally capable of living independently with some community support. When a test reports that a population of 75 million people is dominated by a cohort that is incapable of reading beyond the grade school level and is unable to understand geometry, I tend to be suspicious of the validity of the test, or of the conclusions about ability being drawn from it.

I also have to wonder about the chain of reasoning behind this. I guess when I see a nation wracked by civil war with its infrastructure blown to pieces, a life expectancy of 49 years, and an infant mortality rate of almost 10%, combined with poor performance on some abstract IQ test, my conclusion would be that that situation isn’t exactly conducive to educating children. I don’t see how you would come to the conclusion that they’re just too dumb to live; perhaps the full paper would explain this in some plausible detail.

I don’t have much hope, though. I look at the evolutionary rationale in that abstract and am astonished. So this guy thinks African populations, unlike, say, European populations, have not faced the challenges of “evolutionarily novel problems”? That on an evolutionarily significant timescale, selection has been working on Europeans to generate nearly 40 point differences in IQ from their ancestors, and more improbable still, these same forces haven’t applied to Africans? This is cartoon biology, free of any constraint by fact or theory.

I also don’t have a lot of confidence in work coming out of the London School of Economics. What is it with the wacky stuff coming out of the LSE lately?