Defending Behavior in Bullying and Defenders' Psychosocial Outcomes among Children and Adolescents: A Series of Three-Level Meta-Analyses.

Defending behavior in bullying plays a vital role in mitigating bullying. However, previous research has reported inconsistent findings regarding the potential psychosocial risks faced by defenders. The current study aimed to systematically examine and quantify the associations between defending behavior in bullying and defenders' psychosocial outcomes through a series of three-level meta-analyses. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive systematic search, manual search, and citation tracking were conducted across several databases. The search yielded 290 effect sizes from 62 studies, encompassing data from 102,574 children and adolescents. The analyses revealed that defending behavior in bullying was weakly, but significantly positively correlated with concurrent internalizing problems and victimization. The analyses also showed a small, but reliable positive correlation between defending behavior in bullying and concurrent social relationships, as well as associations with both concurrent and longitudinal social status. These associations were moderated by culture, types of defending, the reporter of defending, and social status types. Positive association between defending behavior and internalizing problems increased with individualism scores. Aggressive defending showed a stronger positive association with internalizing problems than other defending behavior. Both direct defending (particularly aggressive defending) and self-reported defending demonstrated stronger positive correlations with victimization. Defending behavior was more positively linked to likability than popularity. Peer-reported defending was more strongly associated with social status than self-reported defending. However, significant correlations were not observed between defending behavior and externalizing problems or academic achievement. Given the dual nature of defending behavior in bullying, implications for future research directions and bystander intervention programs are discussed.