Individuals develop diverse social attitudes during adolescence. This study focused on adolescents’ cooperative and competitive attitudes from grades 7–11 and their outcomes in grade 12. The sample included 6,908 South Korean adolescents (47.6% girls, mean age = 12.83, range = 12–15). Latent cross-lagged models revealed negative directional associations between cooperative and compet itive attitudes for grades 7–10, but no significant associations for grades 10–11. Cooperative attitudes contributed more to social than academic outcomes, whereas competitive attitudes more positively predicted academic outcomes. The results suggest that educators who support early to mid-adolescents’ cooperative or competitive attitudes need to strike a delicate balance as these attitudes do not change independently and both have distinct strengths and weaknesses.
