Gender differences in optimal sleep duration: girls need slightly longer sleep than boys in most subjects, except mathematics¶

Claim · All claims
Evidence · 1 study · associational r2 · q2
Currency · newest study 2025 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Separate quadratic regressions by gender show both sexes exhibit inverted U-shaped relationships, but optimal sleep differs by subject and gender. → Wang 2025

Evidence¶

Wang 2025¶

Wang, M., Chen, Z., Han, N., & Yao, H. (2025). Sleep duration and subject-specific academic performance among adolescents in China. npj Science of Learning. https://doi.org/10.1038/s41539-025-00361-y

q2 · i? · associational · r2

Gender-specific quadratic OLS models (Table 5) with individual-level covariates, run separately for male and female samples across all five subjects, showing significant inverted U-shapes for both groups with differing vertex values.

"For most subjects, the estimated optimal sleep duration is slightly longer among girls than boys. In contrast, for mathematics, boys show a higher estimated optimal sleep duration than girls"

Discussion¶

Learner Variables¶

• Sleep — predictor: learners who differ on it differ in outcomes

Related Claims¶

• Sleep duration shows an inverted U-shaped association with academic performance in all five subjects, with a peak around 8 hours of nightly sleep — a broader claim this one bears on
• Optimal sleep duration varies by subject: about 8–9 hours for mathematics and 7–8 hours for Chinese, English, science, and arts — related
• Sex-specific subgroup models show the same functional forms for boys and girls, though cubic coefficients for boys were not significant after correction — related
• Sleep duration contributes more to variance in Chinese, mathematics, and science performance than to English and arts, but less than socioeconomic status in every subject — related