View Full Version : Temperature, skin color, per capita income, and IQ: An international perspective

Thursday, December 1st, 2005, 09:54 PM
Temperature, skin color, per capita income, and IQ: An international perspective
Donald I. Templer and Hiroko Arikawa

The impetus for our study was the contention of both Lynn [Lynn, R. (1991). Race differences in intelligence: A global perspective. Mankind Quarterly, 31, 255–296] and Rushton [Rushton, J. P. (1995). Race, evolution and behavior: A life history perspective. New Brunswick, NJ: Transaction; Rushton, J. P. (1997). Race, intelligence, and the brain: The errors and omissions of the revised edition of S.J. Gould's the mismeasure of man. Personality and Individual Differences, 23, 169–180; Rushton, J. P. (2000). Race, evolution, and behavior. A life history perspective (3rd edition). Port Huron: Charles Darwin Research Institute] that persons in colder climates tend to have higher IQs than persons in warmer climates. We correlated mean IQ of 129 countries with per capita income, skin color, and winter and summer temperatures, conceptualizing skin color as a multigenerational reflection of climate. The highest correlations were − 0.92 (rho = − 0.91) for skin color, − 0.71 (rho = − 0.75) for mean high winter temperature, − 0.61 (rho = − 0.68) for mean low winter temperature, and 0.63 (rho = 0.74) for real gross domestic product per capita. The correlations with population of country controlled for are almost identical. Our findings provide strong support for the observation of Lynn and of Rushton that persons in colder climates tend to have higher IQs. These findings could also be viewed as congruent with, although not providing unequivocal evidence for, the contention that higher intelligence evolves in colder climates. The finding of higher IQ in Eurasians than Africans could also be viewed as congruent with the position of Diamond (1997) that knowledge and resources are transmitted more readily on the Eurasian west–east axis.


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Thursday, December 1st, 2005, 10:37 PM
About Jared Diamond I want to add (after an inspiration on Stirpes) that his "environmental" approach which is rather influenced by leftist egalitarian concepts is criticisable, especially because he largely ignores the racial differences and divergent evolutionary parths, but still he has some good points, which, if combined with other ideas and approaches, are very valuable.

Furthermore his environmental view is not just correct to some degree, but is even of importance if looking at the divergent biological evolution you spoke of. So his theories shouldnt be dismissed, other factors and resulting biological consequences for human variation should be just thought with. Because the "highways of knowledge" where usually under high selective pressure and had obviously more and faster "genetic sweeps" as well.

Not to mention the fact I always pointed out, that higher available energy levels and nutrient foods were often preconditions for higher development and their lower level a reason for partial or full stagnation and even degeneration - both by modification and selective pressure, since the modifications usually point in the direction of the selection in a given environment. We can see that over and over again - almost everywhere, and here, again, Diamond had a point, but he just ignored or at least neglected the biological, evolutionary consequences.