The Role of Siblings in Adolescent Delinquency Next to Parents, School, and Peers: Do Gender and Age Matter?

Purpose: This study aimed to explore whether and how sibling delinquency affects adolescent delinquency, over and beyond the effects of other social domains such as parents, school, and peers, and whether this sibling effect is time-varying over the course of adolescence. Methods: Six waves of data from the “Research on Adolescents Development And Relationships-Younger cohort” (RADAR-Y) were analyzed using hierarchical linear modeling (HLM) techniques. Besides an overall model, separate models were tested for the periods of early and late adolescence respectively, in which we accounted for differences in sibling pair composition with regard to gender and age. Results: Sibling’s delinquency was shown to be positively related to adolescent delinquency in early adolescence, only for sister and mixed-sex sibling pairs, but these effects disappeared in later adolescence. In brother pairs, an opposite pattern was observed: sibling delinquency was not related to delinquent behavior in early adolescence, whereas it was in late adolescence. Conclusion: Sibling’s delinquency explains part of adolescents’ delinquency in early adolescence, beyond the influence exerted by peers, parents, and school. Analyzing early and late adolescence in separate models provided a more detailed insight in the influence of sibling’s delinquency over time, and controlling for sex composition reveals that development of sibling similarity in delinquency differs between brothers, sisters, and mixed-sex sibling pairs.