Tracing the delinquency acquisition sequence from older siblings, to friends, to self: A mediation analysis

This study tested the hypothesis that sibling and peer delinquency are connected and that this connection is relevant to future criminal offending.

Drawing on research showing that both sibling and peer delinquency predict future participant offending, a causal mediation analysis was performed on 411 boys from the Cambridge Study in Delinquent Development. In this study, older sibling delinquency served as the independent variable, school problem behavior and friend delinquency served as mediator variables, and participant's reports of their own offending served as the dependent variable.

The indirect effect running from older sibling delinquency at age 10-11, to school problem behavior at age 12-13, to friend delinquency at age 14-15, to participant delinquency at age 16-17 proved significant. The effect remained significant when the number of officially recorded criminal convictions between the ages of 16 and 19 replaced self-reported delinquency as the dependent variable. By contrast, the direct effect from sibling delinquency at age 10-11 to participant delinquency at age 16-17 and several shorter paths (older sibling delinquency → school problem behavior → participant delinquency; older sibling delinquency → friend delinquency → participant delinquency) were non-significant.

These results imply that older sibling delinquency may lead to future delinquency and crime by encouraging early school problems, which, in turn, may precipitate future offending by encouraging the child to select and associate with a delinquent peer group.