This paper uses meta-analysis to examine gender differences in mathematics performance. The authors analyzed data from 242 studies published between 1990 and 2007, involving 1,286,350 participants, and found a negligible gender difference (d = +0.05) and nearly equal male and female variances (VR = 1.08). They also analyzed large U.S. datasets from the past 20 years, finding effect sizes ranging from −0.15 to +0.22 and variance ratios from 0.88 to 1.34. These findings suggest that males and females perform similarly in mathematics. The authors discuss the implications of these results for policy decisions and the persistence of stereotypes about gender and mathematics. They highlight the importance of addressing these stereotypes to encourage women to pursue careers in STEM fields. The study also explores the impact of cultural shifts, such as increased course choices for girls, and the role of variability in mathematics performance. Overall, the findings indicate that gender differences in mathematics performance are small and may be decreasing over time.This paper uses meta-analysis to examine gender differences in mathematics performance. The authors analyzed data from 242 studies published between 1990 and 2007, involving 1,286,350 participants, and found a negligible gender difference (d = +0.05) and nearly equal male and female variances (VR = 1.08). They also analyzed large U.S. datasets from the past 20 years, finding effect sizes ranging from −0.15 to +0.22 and variance ratios from 0.88 to 1.34. These findings suggest that males and females perform similarly in mathematics. The authors discuss the implications of these results for policy decisions and the persistence of stereotypes about gender and mathematics. They highlight the importance of addressing these stereotypes to encourage women to pursue careers in STEM fields. The study also explores the impact of cultural shifts, such as increased course choices for girls, and the role of variability in mathematics performance. Overall, the findings indicate that gender differences in mathematics performance are small and may be decreasing over time.