Gender stereotypes hold that males outperform females in mathematics and spatial tests, and females outperform males on verbal tests. According to meta-analyses, however, among both children and adults, females perform equally to males on mathematics assessments. The gender difference in verbal skills is small and varies depending on the type of skill assessed (e.g., vocabulary, essay writing). The gender difference in 3D mental rotation shows a moderate advantage for males, but this gender difference occurs in the absence of a spatial curriculum in the schools. Meta-analyses of gender differences across a wide array of psychological qualities support the Gender Similarities Hypothesis, which states that males and females are quite similar on most-but not all-psychological variables.