LAUSR

Abstract This study investigated whether early adolescents' disruptive classroom behavior is predicted by descriptive classroom norms for such behavior (i.e., mean level of classmates' disruptive behaviors). We further examined whether classmates' influence on a student's disruptive behavior varies based on teacher's instructional practice. Participants were 701 adolescents ( M  = 13.12 years; 48.8% girls) who were followed across six measurement points from Grades 7 through 9. Multilevel analyses showed that subsequent individual disruptive behavior was predicted by earlier levels of disruptive behavior in the classroom. Peer influence on disruptive behavior was lower when students perceived that their teacher's instruction was more supportive and interesting. When students reported that their teacher used more ability differentiation (e.g., ability grouping), peer influence on disruptive behavior was higher.