We assessed the psychometric properties of the Social Behavior Questionnaire (SBQ), a 30-item questionnaire evaluating social (e.g., disruptive behaviors, bullying) and emotional problems (e.g., anxiety, depression) among children aged 3.5-12 years. Children (n = 1,950, 50.21% boys) were drawn from the Quebec Longitudinal Study of Child…

This study examined the contribution of nonparental child-care services received during the preschool years to the development of social behavior between kindergarten and the end of elementary school with a birth cohort from Québec, Canada (N = 1,544). Mothers reported on the use of child-care services, while elementary school teachers rated…

This study used a genetically informed design to assess the effects of friends' and nonfriends' reticent and dominant behaviors on children's observed social reticence in a competitive situation. Potential gene-environment correlations (rGE) and gene-environment interactions (GxE) in the link between (a) friends' and…

Using a 17-year longitudinal design, this study examined the role of personal and family factors assessed early in life, and also academic and social experiences assessed in the first year of college, in predicting college completion. We followed a sample of 444 French-speaking Canadian children from middle to upper socioeconomic backgrounds (66%…

This study used the monozygotic (MZ) twin difference method to examine whether the unique environmental effects of maternal and paternal overprotection and hostility at the age of 30 months predict twins' observed social reticence in a competitive situation in kindergarten, while controlling for the effect of family-wide influences, including…

Based on a sample of 406 seven-year-old twins, this study examined whether exposure to friends' social or physical aggression, respectively, moderates the effect of heritability on children's own social and physical aggression. Univariate analyses showed that children's own social and physical aggression were significantly explained by genetic…

Evaluated a social process model describing how aggression and withdrawal lead to negative social self-perception. Subjects were 793 French Canadian elementary school children. Found that withdrawal behavior uniquely predicted social self-perceptions. Both negative peer status and peer victimization successively mediated the impact of social…

Examined role of friendship aspects in moderating behavioral antecedents and outcomes of peer victimization among fourth and fifth graders. Teacher-reported internalizing and externalizing behaviors predicted increases in peer-reported victimization; relation of internalizing behaviors to increases in victimization was attenuated for children with…