Gender Diversity Improves Performance but Reinforces Gendered Roles

Does group gender diversity benefit individuals? I examine this question with a field experiment randomizing 3,060 students to small study groups at university entry. Assignment to mixed-gender rather than single-gender groups improves performance and well-being for both men and women: first-year grades increase by about 0.10 SD, well-being by 0.15 SD, and program dropout falls by 6 pp (24%). However, mixed-gender groups also induce more traditional attitudes toward family gender roles. Mechanism analyses suggest that gender diversity fosters collaboration and shifts gender attitudes by reinforcing gendered roles in social interaction: while women coordinate and ask questions, men compete and explain.