As a nation’s economy develops and its standard of living rises, the average intelligence of its inhabitants also increases. But why? In what Faculty of 1000 Member and University of Münster evolutionary biologist Joachim Kurtz calls a “thought-provoking” study, Christopher Eppig suggests that healthier inhabitants could be the answer: Infectious diseases are rarer in developed nations than they are in the developing world, leaving their citizens with more metabolic energy available for cognitive development (Proc R Soc B, doi:10.1098/rspb.2010.0973, 2010).
The intelligence quotient (IQ) test has been used around the world as a measure of cognitive ability. Although controversial, results from these tests have been used to obtain average IQ measures for a nation or geographical region. The average IQ of a country correlates with many factors: temperature, gross domestic product, secondary education, nutrition. And in a nation on its way ...