Sex differences in mathematical abilities

Abstract

Sex differences in mathematical abilities evaluated based on the results of Unified State Examination in mathematics were analyzed. The subjects were 11577 twin pairs who passed through Unified State Examination in mathematics in 2010, 2011, 2012. The sample is representative to Russian Federation twin population of these age cohorts. Differences in mean values and variances and weighted effect size (d) (difference in average scores between boys and girls divided by boys and girls group averaged standard deviation) were evaluated in order to determine sex differences. The main results are as follows: 1. Girls scored lower than boys, on average, in mathematics, but differences were small and significant only for one age cohort (for those who graduated in 2011). The weighted effect sizes (d) for three age cohorts were 0,027, 0,078, 0,028 which represented a negligible gender difference. 2. Boys are slightly more variable, than girls for this measure of mathematical abilities. 3. Girls from opposite-sex twin pairs were better in mathematics, as compared with the girls from same-sex twin pairs (both dizygotic and monozygotic). The findings support assumption that masculinizing hormone (prenatal testosterone) affects sex differences.