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…

Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status,…

This study had three goals: (a) assessing the predictive association of externalizing and internalizing behaviors during childhood with sexual onset during early adolescence; (b) examining the interactive link of externalizing and internalizing behaviors with early sexual onset; and (c) investigating the moderating effect of gender in this…

The goal of the present study was to examine whether controlling parenting contributes to the problem of physical aggression. Developmental trajectories of children's physical aggression were modeled from yearly teachers' ratings, from ages 6 to 12. Multinomial logistic regressions (N = 1,508) served to identify risk factors that distinguish…

We examined the influence of income source within the context of persistent poverty on children's disruptive classroom behavior at age 12 and whether these associations were mediated by maternal supervision at ages 10 and 11. Using a subsample (N = 1,112) from the Quebec Longitudinal Study, we coded four economic circumstances indicating…

Compared sociometric and behavioral measures of two-year (kindergarten to grade two, or grade one to grade two) and 1-year (kindergarten-only or grade-one-only) rejected children. Concluded that it was possible to identify at-risk, two-year rejected children as early as kindergarten by means of combined sociometric and behavioral data. (GLR)

Using a prospective design spanning 17 years, the authors studied in a sample of 231 boys and girls the predictive links of verbal abuse by the teacher during childhood to high-school graduation and behavioral and emotional problems in young adulthood, as well as the putative mediating role of individuals' generalized and domain-specific…