Gender Differences in Variability in Intellectual Abilities: A Reanalysis of Feingold’s Results

The joint effects of gender differences in mean and variability on 28 cognitive ability scales were recently examined by Feingold (1992a). He noted that gender differences in extreme score ranges (e.g., in the tails of the distribution of scores) may be influenced by differences in both mean and variability and offered subjective evaluations of effect sizes in the center and tails of these distributions. We provide an analytic evaluation of the effect sizes in the tails and show that the effect sizes in the tails of these distributions are typically smaller than Feingold assumed. We also evaluate the joint effect of gender differences in mean and variability via a different index: the number of females and males in the extreme score ranges. Males outnumber females in the upper tail of the score distribution of 22 of 28 ability scales, including 3 of the scales in which females have a higher overall mean.