I hope some enterprising journalist tracks down our Professor Flynn in Dunedin to get his views on the report just noted in the Economist, that links average country IQs with their ranking for the  prevalence of infectious diseases.

"A rise in intelligence over the decades has already been noticed in rich countries. It is called the Flynn effect after James Flynn, who discovered it. Its cause, however, has been mysterious—until now".

The report summarises the findings:

"At the bottom of the average-intelligence list is Equatorial Guinea, followed by St Lucia. Cameroon, Mozambique and Gabon tie at third from bottom. These countries also have among the highest burden of infectious diseases. At the top of the list of countries with the highest average intelligence is Singapore, followed by South Korea. China and Japan tie in third place. These countries all have relatively low levels of disease. America, Britain and a number of European countries, follow behind the leaders. A list of the countries included in the study can be found at: www.economist.com/science-technology"

I'm puzzled by the indication that China has low disease prevalence. If it is indeed comparable with the wealthy west that is a phenomenal acheivement, given their relative poverty, population density, and the use of human dung as fertiliser.