Examined peer group contextual effects on relations between academic achievement and social functioning among Chinese 9-, 13-, and 16-year-olds. Found that peer groups were highly homogeneous on academic achievement. Academic achievement and social adjustment were associated at within-group individual and group levels. Group academic performance moderated relations between academic achievement and social adjustment (peer acceptance, social competence, and leadership), suggesting that individual-level relations are influenced by group academic norms. (Author/KB)