"Black" vs "White" IQ scores
    The data for the two curves were collected in the 1960's, from 1800 Afro-American school children, and a "normative" group of "White" children. The difference between the means is about 20 points; the variance of the "black" curve is smaller. The difference between groups has variously been argued to be environmental (e.g., differential school quality) or innate ("genetic").

All text material © 2010 by Steven M. Carr