The Economist reports a scientific finding that links nutrition and disease burden to human intelligence. The findings add to the development debate by suggesting that disease burden, through its effect on brain development, is a significant predictor of a country’s average intelligence level and that this in turn may explain endemic underdevelopment within the tropics. The questionable inferences from the research findings aside (see the comments section of the Economist article) my two cents on this is that it doesn’t matter. Firstly, a low average does not preclude outliers on the right hand side. And secondly, a country only needs so many Einsteins (Read Debraj and others on the impact of tertiary education on development). Plus after reading Bernstein I can bet that the average Sri Lankan or Chadian is still smarter than the average Renaissance man, despite the latter’s spectacular achievements.
What really matters for economic development are Institutions and the rule of law. These can help countries survive even not so bright leaders – Bush’s America is a good example here. Of course the bigger problem is that it might be the case that you need a high national average intelligence to maintain self-reinforcing institutions that promote development. But even this would be a tough sell given the high variance in institutional capacity across different countries with different disease burdens (contrast Cuba with some of the poorer and sicker but higher ranked countries for instance).
The causal link between poor nutrition, a high disease burden and cognitive development probably exists. But I don’t think that the impact is large enough to explain underdevelopment in the global South. Just until 150 years ago there was not much variation in the average life expectancy across the different regions of the world despite the disparate development levels.
The complete list is here
update: Here is a paper that documents the secular increase in IQ levels in Sudan. In light of the above article, poor countries need not worry. It appears that modernization will take care of their low average IQ worries.