Since a lot of voice cards have been addressing inteligence, sex differences, and statistics to this point, I thought that this would be as good a place as any to discuss an old chapter on intelligence that I recently dug up (Lehrke, 1978 - Sex linkage: A biological basis for greater male variabilty in intelligence. In Osborne, Noble, and Wyle, Eds., Human Variation).

This article primarily focusses on research defending the rather old idea that females show lower variance on IQ tests than males - a difference attributed to sex linkage. The "evidence" used is somewhat complex, but relies much on intra-familial correlations for IQ. Thus, sex linkage would lead one to expect that the correlation of test scores for mother-daughter, mother-son, and father-daughter would be somewhat similar, because the parent and child in each case would have one X-chromosome in common. The correlations between fathers and sons would be lower since they have no X-chromosomes in common, and the correlation between siblings would be intermediate because they have an X-chromosome in common half of the time. Results reported by Lehrke support this hypothesis.