In July, researchers at the University of New Mexico proposed a new explanation behind varied overall intelligence averages from country to country – the effect of infectious disease.

Christopher Epigg and his colleagues explain that that the brains of newly born children require 87% of those children’s metabolic energy (44% for five-year olds). “Any competition for this energy is likely to damage the brain’s development, and parasites and pathogens compete for it in several ways.” Some parasites that live in the gut stop their hosts from absorbing food and preventing nutritional absorption. All of these effects lead to hindered brain, cognitive, and bodily development. 

After controlling for other causes, the correlation that Epigg and his colleagues found was remarkable. Equatorial Guinea, St Lucia, Cameroon, Mozambique and Gabon fall at the bottom of the average-intelligence list. They are also some of the countries that have the highest burden of infectious disease. As explained by an article in the Economist, “If they are right, it suggests that the control of such diseases is crucial to a country’s development in a way that had not been appreciated before.”
 

Read the article in The Economist>>