Peer group interactional style was examined as a moderator of the relation between peer group school misconduct and group members' school misconduct. Participants were 705 students (M[subscript age] = 11.59 years, SD = 1.37) in 148 peer groups. Children reported on their school misconduct in fall and spring. In the winter, group members were observed in a limited-resource task and a group conversation task, and negative and positive group interactional styles were assessed. Multilevel modeling indicated that membership in groups that were higher on school misconduct predicted greater school misconduct only when the groups were high on negative or low on positive interactional style. Results suggest that negative laughter and a coercive interactional style may intensify group effects on children's misconduct.