Sibling Bullying, Aggression and Abuse in Childhood and Adolescence: A Scoping Review and Meta-Analysis of Prevalence, Predictors, and Outcomes.

Sibling aggression and abuse (SAA), historically known as sibling bullying, reflect prevalent and unique family vulnerabilities. However, a lack of global data integration hinders a full understanding of this issue. This study synthesized evidence on the prevalence, predictors, and outcomes of SAA during childhood and adolescence. Searches of 5 databases identified 117 eligible studies, including child/adolescent samples (n = 87) and adult retrospective samples (n = 30). Pooled prevalence estimates indicated that SAA was common across involvement subtypes, including victimization (37.7%), perpetration (35.8%), overall involvement without role distinction (33.3%), and mutual involvement (30.2%). Guided by the social-ecological framework for predictors and the biopsychosocial model for outcomes, the synthesis identified parent-child violence/conflict as the strongest predictor of SAA (r = .503, 95% CI [0.173, 0.834]) and trauma-related symptoms as the strongest outcome correlate (r = .434 [0.240, 0.628]). Subgroup analyses showed no significant differences in prevalence by sample type or assessment frame, whereas meta-regression suggested that selected estimates varied by mean age and the percentage of females. This review provides an integrated synthesis of the prevalence, predictors, and outcomes of SAA during childhood and adolescence, with implications for the development of comprehensive and evidence-based intervention strategies.