This research examined parents' restriction of children's peer relationships in the United States and China. American and Chinese children (N = 934; M[subscript age] = 12.67 years) reported on their parents' peer restriction (e.g., limiting children's time with peers) and their behavioral and psychological adjustment 3 times over a year.…

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 investigated the effects of internal and demographic variables on civic development in late adolescence using the construct "civic purpose." We conducted surveys on civic engagement with 480 high school seniors, and surveyed them again 2 years later. Using multivariate regression and linear mixed models, we tested the main…

This study investigated the normative use and developmental course of physical aggression (PA), defined as use of physical force such as hitting, biting, and kicking, from 8 to 26 months and predictors thereof. We used data from the Behavior Outlook Norwegian Developmental Study, comprising 1,159 children (559 girls and 600 boys). Both mothers and…

Developmental science is replete with studies on the impact of mothers on their children, but little is known about what might best help caregivers to function well themselves. In an initial effort to address this gap, we conducted an Internet-based study of over 2,000 mostly well-educated mothers, seeking to illuminate salient risk and protective…