Our aim was to assess whether infants influence the quantity and quality of their mothers' speech to them and, in turn, whether this maternal speech influences children's later language. As 189 mothers interacted with each of their twins at age 0;5, we calculated the number of utterances, the proportion of sensitive utterances, and the proportion…

This study aimed to identify joint trajectories of peer cyber and traditional victimization from ages 13 to 17 and individual, family, peer, and school risk factors associated with group membership. The sample was composed of 1,194 adolescents (54.2% girls). Cyber and traditional victimization were assessed at ages 13, 15, and 17. The results…

The associations between trajectories of child care quality from ages 2 to 4 years and children's cognitive performance at 4 years ("n" = 250) were tested. Distinct quality trajectories were identified: low and high ascending Teaching and Interactions trajectory; low and high Provision for Learning trajectory. Membership in the high…

Enriched environments may moderate the effect of genetic factors on prosocial leadership (gene-environment interaction, G × E). However, positive environmental experiences may also themselves be influenced by a genetic disposition for prosocial leadership (gene-environment correlation, rGE). Relating these processes to friendships, the present…

Background: The juvenile justice system's interventions are expected to help reduce recidivism. However, previous studies suggest that official processing in juvenile court fails to reduce adolescents' criminal behavior in the following year. Longer term effects have not yet been investigated with a rigorous method. This study used propensity…

Impairments in either "cool" or "hot" processes may represent two pathways to deficient decision-making. Whereas cool processes are associated with cognitive and rational decisions, hot processes are associated with emotional, affective, and visceral processes. In this study, 168 boys were administered a card-playing task at ages 13 and 14 years…

The authors examined the role of familial risk and child characteristics in the association between the type of child care in infancy (maternal care [MC]) versus nonmaternal care [NMC]) and emotional/behavioral difficulties at 4 years old. Canadian families (N=1,358) with children between 1 and 12 months old were followed over 4 years. Family…

Background: Three different explanations have been given for the observation that adolescent gang members report more delinquent behaviour than their counterparts who do not affiliate with gangs: a) adolescents who commit more crimes join gangs (selection hypothesis); b) gang membership facilitates deviant behaviour (facilitation hypothesis); c)…

The study identified independent individual, family, and neighborhood correlates of children's physical aggression and prosocial behavior. Participants were 2,745-11-year olds nested in 1,982 families, which were themselves nested in 96 Canadian neighborhoods. Hierarchical linear modeling showed that the total variation explained by the…

Predictors of school dropout and their stability over time were studied in 791 white French-speaking Canadian students aged 12 to 16 years in 1974 and 791 similar students in 1985 through self-administered questionnaires. School, family, behavioral, social, and personality variables predicted dropping out in both samples, and these predictors were…