Performed a meta-analysis of 100 studies of gender differences in mathematics performance. They yielded 254 independent effect sizes, representing the testing of 3,175,188 Ss. Averaged overall effect sizes based on samples of the general population indicated that females outperformed males by only a negligible amount. An examination of age trends indicated that girls showed a slight superiority in computation in elementary school and middle school. There were no gender differences in problem solving in elementary or middle school; differences favoring men (...) emerged in high school and college. Gender differences were smallest and actually favored females in samples of the general population, grew larger with increasingly selective samples, and were largest for highly selected samples and samples of highly precocious persons. The magnitude of the gender difference has declined over the years. Gender differences in mathematics performance are small. Nonetheless, the lower performance of women in problem solving that is evident in high school requires attention. (shrink)

[Correction Notice: An erratum for this article was reported in Vol 136 of Psychological Bulletin. On page 118 of the article “Cross-National Patterns of Gender Differences in Mathematics: A Meta-Analysis,” by Nicole M. Else-Quest, Janet Shibley Hyde, and Marcia C. Linn, the images on Figures 1 and 2 are incorrectly reversed. The legends for Figures 1 and 2 are in the correct order.] A gender gap in mathematics achievement persists in some nations but not in others. In light of the (...) underrepresentation of women in careers in science, technology, mathematics, and engineering, increasing research attention is being devoted to understanding gender differences in mathematics achievement, attitudes, and affect. The gender stratification hypothesis maintains that such gender differences are closely related to cultural variations in opportunity structures for girls and women. We meta-analyzed 2 major international data sets, the 2003 Trends in International Mathematics and Science Study and the Programme for International Student Assessment, representing 493,495 students 14–16 years of age, to estimate the magnitude of gender differences in mathematics achievement, attitudes, and affect across 69 nations throughout the world. Consistent with the gender similarities hypothesis, all of the mean effect sizes in mathematics achievement were very small ; however, national effect sizes showed considerable variability. Despite gender similarities in achievement, boys reported more positive math attitudes and affect ; national effect sizes ranged from d = −0.61 to 0.89. In contrast to those of previous tests of the gender stratification hypothesis, our results point to specific domains of gender equity responsible for gender gaps in math. Gender equity in school enrollment, women’s share of research jobs, and women’s parliamentary representation were the most powerful predictors of cross-national variability in gender gaps in math. Results are situated within the context of existing research demonstrating apparently paradoxical effects of societal gender equity and highlight the significance of increasing girls’ and women’s agency cross-nationally. (shrink)