Autonomy-supportive teaching increases prosocial and decreases antisocial behavior. Previous research showed that these effects occur because autonomy-supportive teaching improves students' need states (a student-level process). However, the present study investigated whether these effects also occur because autonomy-supportive teaching improves the classroom climate (a classroom-level process). Teachers from 80 physical education classrooms were randomly assigned to participate (or not) in an autonomy-supportive teaching intervention, while their 2,227 secondary-grade students reported their need satisfaction and frustration, supportive and hierarchical classroom climates, and prosocial and antisocial behaviors at the beginning, middle, and end of an academic year. A doubly latent, multilevel structural equation model showed that teacher participation in the intervention (experimental condition) increased class-wide need satisfaction, a supportive climate, and prosocial behavior and decreased class-wide need frustration, a hierarchical climate, and antisocial behavior. Together, greater collective need satisfaction and a more supportive climate combined to explain increased prosocial behavior, while lesser need frustration and a less hierarchical climate combined to explain decreased antisocial behavior. These classroom climate effects have been overlooked, yet they are essential to explain why autonomy-supportive teaching improves students' social functioning.
