In the recent post on IQ regression to the mean, reader Levi Johnston asked if there were enough black respondents to calculate IQs for those with two highly educated parents, not one or two. The n for blacks drops from 47 to 16--a small sample, indeed--but the results are a mean of 109.6 for whites and 105.3 for blacks (the difference is not statistically significant). Compared to the earlier results, scores went up a couple points for whites but five points for blacks. The gap in standard deviation (sd) terms shrunk from around half to about three-tenths.
I should note that with the full sample of blacks and whites, the IQ gap based on the GSS vocabulary test in only about 10 points--not the usual 15. This is probably due to the fact that the test taps verbal IQ, a form of intelligence with a smaller racial gap. For the full sample, the black-white difference is only two-thirds of an sd--not the one sd difference that researchers usually observe when looking at general intelligence.