Many explanations have been proposed for the evolution of our anomalously large brains, including social, ecological, and epiphenomenal hypotheses. Recently, an additional hypothesis has emerged, suggesting that advanced cognition and, by inference, increases in brain size, have been driven over evolutionary time by the need to deal with…

A large number of national and geographic population samples were used to test the hypothesis that the variation in mean values of skin color in the diverse populations are consistently correlated with the mean measured or estimated IQs of the various groups, as are some other physical variables, known as an ecological correlation. Straightforward…

This statement signed by 52 researchers outlines conclusions regarded as mainstream among researchers on intelligence, especially on the nature, origins, and practical consequences of individual and group differences in intelligence. The survey from which the statement was developed is described. (SLD)

The president of the Pioneer Fund, a nonprofit foundation that makes grants into studies of individual and racial differences, addresses some of the media attacks on the fund in the context of the nature-nurture controversy. (SLD)

Data used to support Spearman's hypothesis have been incorrectly and inconsistently reported and do not support the claim that African-American-white differences in intelligence are not environmental in origin. Deaf children should not be considered a single population with respect to linguistic deprivation. (SLD)

Two studies with 658 white and 353 African-American elementary school children performing reaction time tasks are offered in support of Spearman's hypothesis about the relative size of the mean African-American-white differences on mental tests as a function of the tests' loadings on psychometric "g." (SLD)