This investigation examines the spread of problem behaviors (substance use and delinquency) between twin siblings. A sample of 628 twins (151 male twin pairs and 163 female twin pairs) drawn from the Quebec Newborn Twin Study completed inventories describing delinquency and substance use at ages 13, 14, and 15. A 3-wave longitudinal actor-partner…

This study examined the associations between sibling intimacy and conflict and youths' reports of risky behavior in a sample of adolescents ages 11-20. Participants were mothers, fathers, and sibling dyads in 393 families who were interviewed annually for 3, 4, or 5 years. Multivariate multilevel models tested longitudinal links between sibling…

This study investigated the prospective links between sibling aggression and the development of externalizing problems using a multilevel modeling approach with a genetically sensitive design. The sample consisted of 780 adolescents (390 sibling pairs) who participated in 2 waves of the Nonshared Environment in Adolescent Development project.…

Examined the relation between destructive sibling conflict and conduct problems among 5-year-old boys and their close-age siblings from low-income families. Found that the interaction between destructive sibling conflict and rejecting parenting predicted aggressive behavior problems across time and informants. Sibling conflict was related…