From Norms to Behavior: Examining the Mechanisms of Change in a Social Norms Anti-Bullying Intervention Among Early Adolescents

Social norm interventions offer a promising approach to bullying prevention, yet the mechanisms through which they operate remain unclear. Using a parallel mediation structural equation model, this study examined potential mediators of a classroom-based social norms intervention previously shown to reduce direct and indirect bullying. Participants were 809 students (52.78% female; M _age  = 10.15, SD _age  = 0.98) from Grades 4 to 6 in six schools (36 classes) randomly assigned to an intervention or control condition. Results showed that changes in direct bullying were mediated by changes in injunctive anti-bullying norms among most liked classmates, whereas the mechanisms underlying changes in indirect bullying remained unexplained. Individuals’ perceptions of classroom, friend and teacher norms were unaffected by the intervention, challenging the widely held assumption that norm interventions operate through (conscious) norm perceptions. These findings highlight the importance of explicitly testing mediating pathways and identifying the reference groups through which norm-based interventions exert their effects.