Abstract
Reputational peer nominations are a common method for measuring involvement in aggression-related behaviors, encompassing the roles of aggressor, victim, and defender, but may be influenced by students' affective (dis)liking relationships. This social network study investigated whether dyad- and group-level (dis)liking relationships affect perceptions of classmates' involvement in physical aggression and explored the moderating roles of classroom moral disengagement and defending norms. The study employed a longitudinal design with two time points 6 months apart, encompassing 27 classrooms and 632 early adolescents. Using multiplex stochastic actor-oriented modeling, we found that liking, but not disliking, significantly influenced perceptions. Liking a classmate increased the likelihood of perceiving them as a defender. Moreover, students' own perceptions (aggressor, victim, and defender nominations) were shaped by the perceptions of classmates they liked, while classroom moral disengagement reduced this influence for defender nominations. Results on classroom defending norms were mixed. Our findings underscore the importance of accounting for students' liking relationships and classroom-level norms to reduce bias in peer nominations and improve the accuracy of assessments of aggression-related behaviors.