Sisters, brothers, and delinquency: Evaluating social influence during early and middle adolescence

Although a number of studies have shown that brothers are highly correlated fur delinquent behavior, much less research has been conducted on sisters. We propose that sisters, like brothers, show notable similarity for delinq uent behavior, and also promote each other's delinquency through direct int eraction. We examined these issues in 164 brother and sister pairs studied over a 4-year period (from early to middle adolescence) in a study of intac t families in the rural Midwest. Sibling similarity for self-reports of del inquent behavior were highly correlated for both brothers and sisters. Cond itional effects of high levels of hostile-coercive sibling relationships an d older sibling delinquency predicted younger sibling delinquency in both b rother and sister pairs. For brothers, conditional effects were also detect ed for high levels of warmth-support, in contrast to sisters. The condition al effects of older sibling delinquency and relationship quality were shown to predict change in younger sibling delinquency through adolescence. The results add to a growing literature on sibling effects as well as theoretic al models that emphasize the role of social interaction between siblings as a risk factor for the development of delinquent activity in adolescence.