Sibling influences on adolescent delinquent behaviour: an Australian longitudinal study.

This article examines sibling influences on adolescent delinquency at age 14, using data from an Australian longitudinal study of 374 same- and mixed-sex sibling pairs. Based on maternal and self-reports, a moderately strong association between siblings' delinquency is found. The relationship remains significant controlling for childhood aggression and family environment factors measured during childhood (age 5) and adolescence (age 14), using both standardized instruments and new scales. This effect varies according to the sex composition of the sibling pair and is stronger for males and those whose parents have been arrested. The need for increased attention to sibling influences by researchers and prevention practitioners is discussed.