‘The Cycle of Sibling Bullying’: Exploring the Links Between Sibling Bullying Victimization, External Support and Parent–Child Decision‐Making in Multichild Families

ABSTRACT Sibling bullying in multichild families involves concealed power dynamics, where victims' voices are often unheard by both their families and external sources, resulting in prolonged oppression and violence. Given the unclear impact of sibling bullying victimization on parent–child decision‐making, this study investigates the relationship and explores whether external support serves as a compensatory resource allocation mechanism in families struggling with equitable resource distribution. Based on data from a sample of 10 164 children in the International Survey of Children's Well‐Being, the research reveals that children experiencing sibling bullying are less likely to make joint decision‐making with their parents, and external support mediated the relationship between sibling bullying victimization and parent–child decision‐making, which suggests that victims of sibling bullying often feel isolated and unsupported by their families. Although external support is a vital resource to help children overcome the negative impacts of sibling bullying, its limited availability leaves victims trapped in a persistent cycle of sibling bullying—a state characterized by ongoing experiences of victimization. This research enhances the understanding of how sibling bullying influences parent–child decision‐making and offers valuable prevention and intervention strategies for parents, teachers and social workers to address resource imbalances and implement effective support measures.