Sex differences in the intellectual functioning of early school-aged children in rural China

BACKGROUND Gender disparities in China are concentrated in poor rural areas and among poor households. The difference in intelligence between boys and girls is less clear in rural China. The purpose of this paper was to assess sex differences in the intellectual function of early school-aged children in rural China. METHODS One thousand seven hundred forty four early school-aged offspring of women who had participated in a prenatal supplementation trial with different combinations of micronutrients and continued to reside in two rural counties in China were followed. We measured their Full-Scale IQ (FSIQ), Verbal Comprehension Index (VCI), Working Memory Index (WMI), Perceptual Reasoning Index (PRI) and Processing Speed Index (PSI) using the Wechsler Intelligence Scale for Children (WISC-IV). Multilevel analyses were used to assess sex differences in intellectual functioning in 7-10-year-old children in rural China. RESULTS Boys' adjusted mean FSIQ score was 0.97 points higher (95% CI: -2.22 - 0.28) than that of girls. Girls obtained higher mean WMI and PSI scores, with 1.32 points (95% CI: 0.14 - 2.51) and 3.10 points (95% CI: 1.82-4.38) higher adjusted means, respectively. Boys' adjusted mean VCI and PRI scores were significantly higher than those of girls, and the mean differences were 2.44 points (95% CI: 0.95 - 3.94) and 3.68 points (95% CI: 2.36 - 5.01), respectively. CONCLUSIONS There is no evidence to suggest sex differences in the general intelligence of early school-aged children in rural China. However, a difference in general intelligence between 10-year-old boys and girls was evident. Girls and boys in rural China tended to show different specific cognitive abilities.