Sex differences in visual spatial ability in 9-year-old children

Sex differences in spatial ability have not been reliably demonstrated in prepubertal children. This could in part be due to the lack of age-appropriate and reliable tests. In this study, adult versions of multiple-choice tests measuring three different spatial ability categories were adapted for use with 9-year-old children. Sex differences of 0.6 to 0.8 and 0.4 standard deviation units were found in mental rotation and spatial perception, respectively, indicating that reliable sex differences in spatial ability are present in prepubertal children. A small (0.2) and nonsignificant difference appeared in spatial visualization. These effect sizes and their distribution across categories are similar to meta-analytic results based on adolescent and adult data. Analyses of test intercorrelations showed that the shared variance among tests was higher in boys than in girls, suggesting that spatial ability is a more unified trait in boys as compared to girls, in whom spatial abilities are more heterogeneously organized.