WORDSUM and spatial IQ: Audacious has a post up on the ability of WORDSUM in the General Social Survey to capture IQ. Steve Sailer commented that since it's a vocabulary test, it might fail to pick up important abilities like spatial intelligence.
I found a study of American students by Lynn (Personality and Individual Differences, Vol. 20, No. 2, pp. 271-273, 1996) which reported spatial IQ scores for whites, blacks, Hispanics and Asians. Using WORDSUM, I calculated mean IQs for each of the four groups and then estimated a correlation across the four groups. It was .98. Admittedly, it's an N of 4, but the results are reassuring nevertheless.