Social interdependence theory proposes that task structure influences performance via social interaction. Using this framework, we examined sport performance. Fifty-six males performed a basketball task under four conditions: as an individual (individual, perform your best) and as a member of a team of two (cooperation, where teammates sought to better their individual performance; means independent competition, where two teams competed sequentially to outperform the other team; means interdependent competition, where two teams competed simultaneously to outperform the other team). Task performance (points) was better during means independent competition than other conditions. Anxiety and effort peaked during the competitions and enjoyment was greater during competition and cooperation than during the individual condition. Emotions, effort, and actions are discussed as explanations for the performance effects. Social interdependence theory provides a valuable
framework to understand emotion, motivation, and performance. Team competition can be used to promote effort and enhance performance in sport.