Longitudinal data from 746 adolescents in Toronto, Canada (54% females), was gathered in eight waves over seven years (1995 through 2001), beginning when the youths were 10 to 12 years old (mean age = 11.8, SD = 1.2 years). Five trajectories of substance use were identified: chronic-high, childhood onset-rapid high, childhood onset-moderate,…

Using data from a longitudinal study of Mexican-origin girls (ages 11-17 at Time 1), we examined sociocultural (i.e., family structure, nativity, and acculturation), interpersonal (i.e., supportive parenting and conflict), and developmental (i.e., menarche timing and autonomy expectations) predictors of sexual initiation. Using Cox proportional…

Developmental theory describes the central importance of peer relationships in the lives of young adults (e.g., Erikson, 1963). In this study we tested the importance of peer relationships to academic outcomes. First-year undergraduates completed a self-report survey to indicate the number and closeness of their friendships. We compared these…

In this study, the validity of a self-report measure of children's perceived attachment security (the Kerns Security Scale) was tested using adolescents. With regards to predictive validity, the Security Scale was significantly associated with (1) observed mother-adolescent interactions during conflict and (2) parent- and teacher-rated social…

According to developmental research, peer relationships serve a positive function in children's, adolescents', and adults' lives. We expected that peer relationships would also benefit emerging adults as they transition into college. Using friendship quality and attachment measures, we examined the link between the closeness of peer relationships…