Ecological correlations between IQ, skin color, temperature and GDP per capita

The researchers (Donald Templer and Hiroko Arikawa) computed the correlations between the predominant skin color in 129 nations, GDP per capita, high and low mean temperatures in the summer and winter, and skin color. The correlation between predominant skin color and population IQ was − 0.92!

For those not familiar with correlation coefficients, these range in magnitude from 0 (no correlation) to 1 (perfect correlation). The sign of the correlation coefficient indicates the directionality of the correlation. Thus, given that predominant skin color was rated from 1 (white) to 8 (black), since lower values of skin color correspond to higher IQs, the correlation is very strongly negative.

Note that the correlations are at the level of populations, not individuals. Nations comprising of indigenous populations were selected (a total of 129); the excluded nations are either largely comprised of diaspora populations or did not have skin color data. Controlling for population size of different nations did not significantly change the correlations. The correlation between skin color and IQ remained the same even if India (IQ = 81) was excluded (in India, whereas the predominant skin color was rated 6.33 on the 1-8 scale mentioned above, skin color ranges from near-white to black).

The IQ data were taken from the summary of Lynn and Vanhanen. Actual IQ data were available from 55 selected nations and IQ data for 74 nations were estimated based on their racial composition and the known IQ of their neighbors. For the 55 nations whose IQ data were available, 50 national averages were based on the Raven’s Progressive Matrices Test and/or the Cattell Culture Fair Test, “both tests being devoid of educational and specific cultural content.”


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


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 [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 mismeasurement 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 Ā0.92 (rho =Ā0.91) for skin color, Ā0.76 (rho =Ā0.76) for mean high winter temperature, Ā0.66 (rho =Ā0.68) 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. m+skin+color+intelligence&hl=en&gl=au&pi d=bl&srcid=ADGEESjGbZP0MBExXvCnzOm3VlL1S TiVJO-E2YZu6QVi5flchMXrH4kfd7qKx_hT8Rn_pMGmq1-gl5qf4nhjj6XQ9KffnTADqvOC4pCQVCqJiGFlDMo GXY1drQfeqH1eBydUg7DIWDl7&sig=AHIEtbTagq SKk_wotM-UI4okjAkYVH-Cwg