IQ Score Variations by Nation

This is a weekly post by Nidhal Guessoum (see his earlier posts here). Nidhal is an astrophysicist and Professor of Physics at American University of Sharjah 

The question of whether IQ (Intelligence Quotient) scores vary (significantly) from country to country may sound terribly racist and unapproachable. But first, no question, if honestly asked and investigated, should be taboo; and second, the question sounds racist only if one believes that any such differences (if found) will be attributed to racial characteristics, rather than developmental factors.

Now, one of the main scientific problems that pose themselves whenever this issue is studied (seriously, objectively) is the fact that IQ tests are quite invariably fraught with cultural effects. In a previous post, I had reported on how easily we can mistake some common traits that we are used to around us for “human universals”. So one can imagine that measuring intelligence “universally” is a very complicated matter. (I remember once I took a French IQ test – for fun – and many of the verbal questions had some “well-known” cultural assumptions that were alien to me, and I’m totally fluent in French…)

Many countries, however, do have huge databases of IQ test results for their people, by age, education level, economic status, year, etc. Now, again, comparing results from different countries is a very risky exercise, but looking at scores within each country, and studying their variations through time can be recommended. And that’s what James Robert Flynn (born 1934), Emeritus Professor of Political Studies at the University of Otago in Dunedin, New Zealand, did some years ago, at which point he noticed what has become known as the Flynn Effect: IQ scores have been steadily increasing every decade now for over sixty years, in all countries that keep such data. Why is that? There are various hypotheses for this, ranging from cognitive abilities improving with more stimuli coming to our minds from more sophisticated educational, social, and economic environments to improved nutrition allowing the brain to perform its tasks better and faster…

Controversially, some researchers have postulated a reverse correlation between IQ and development level; that is, countries with higher average IQ’s will reach greater economic levels, not the other way around. Indeed, in two very controversial books (“IQ and the Wealth of Nations”, 2002, and “IQ and Global Inequality”, 2006), Richard Lynn, Professor Emeritus of Psychology at the University of Ulster, Northern Ireland, and Tatu Vanhanen, Professor Emeritus of Political Science at the University of Tampere, Tampere, Finland, argue that current differences in economic development are due at least in part to differences in average national IQ scores…

But a recent study found an interesting correlation between average IQ scores and rates of infectious diseases in various countries. More clearly, the more widespread is malaria, for instance, the lower the average IQ will be in that country… That’s what Christopher Eppig (a Ph.D. candidate in biology at the University of New Mexico, Albuquerque) and his colleagues reported in a paper they published in July in the Proceedings of the Royal Society B (see the diagram below, from New Scientist).

How could those two factors (IQ and infectious diseases) be correlated? The interpretation that has been offered holds that parasitic infections rob the body – and thus the brain – of infants of much energy and divert body resources to fighting the disease and pumping up the immune system, hence reducing the capacity of the brain to perform at higher rates and levels.

The researchers insist that they did control for other factors that could affect IQ scores, including education opportunities, income levels, and even climate (as colder lands have been theorized to help improve IQ scores… from an evolutionary perspective…).

If such an effect and its proposed explanation are confirmed (by other studies), this could constitute an important phenomenon for national and international institutions (e.g. the World Bank) to address, in an attempt to hit several birds with one stone…