Data: Sex and race differences in self-rated athletic ability

One study of athletic performance put heritability at .66.  In plain English, two-thirds of the differences in athletic ability are explained by genetic differences.

General Social Survey participants were asked to rate how athletic they are on a scale from 1 to 5.  I calculated the means for sex and race combinations (N = 2,373):

Black men rate themselves as most athletic with a mean of 3.57.  White women (2.58) and women of some other race (2.56) come in at the bottom.  The gap between black men and other-race women is nine-tenths of a standard deviation (SD) -- a big difference.

If we focus on just men, the black-white difference is one-third of an SD -- a small advantage for black men.

The biggest within-race gap is among blacks: the male advantage over females is three-quarters of an SD.  The graph doesn't show the overall sex difference: it's over half of an SD.

While it's difficult to rate oneself objectively, these self-ratings seem to have some validity.