"For 104 of the 185 nations, no studies were available. In those cases, the authors have used an estimated value by taking averages of the IQs of neighboring or

"For 104 of the 185 nations, no studies were available. In those cases, the authors have used an estimated value by taking averages of the IQs of neighboring or comparable nations. For example, the authors arrived at a figure of 84 for El Salvador by averaging their calculations of 79 for Guatemala and 88 for Colombia. Including those estimated IQs, the correlation of IQ and GDP is 0.62. To obtain a figure for South Africa, the authors averaged IQ studies done on different ethnic groups, resulting in a figure of 72. The figures for Colombia, Peru, and Singapore were arrived at in a similar manner." http://en.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations#National_IQ_estimates http://en.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations#Na... Seriously? If that's not enough: "This is not so much science, then, as a social crusade. The Pioneer Fund of America, champion of many dubious causes in the past, will obtain little credit from having assisted this one. The myriad corrections and estimates aside, this is a blast from another age, an old-fashioned attempt to give an imperial mindset biological validity." http://www.nature.com/hdy/journal/v92/n4/full/6800418a.html http://www.nature.com/hdy/journal/v92/n4/full/6800418a.html