The risk of delinquent to antisocial behaviors among youth (teenagers) seem to be more prevalent in group homes than other foster homes. The aim of this study was to examine the association between negative peer influence and youth antisocial behaviors in group homes. Participants were 875 youth aged 10 to 17 at baseline (2010-2011). Logistic…

Youth today spend a tremendous amount of time with digital media. The purpose of the present study was to estimate developmental associations between screen media use between the ages of 15 and 17 and corresponding changes in prosocial behavior. Participants (N = 1,509) were part of the Quebec Longitudinal Study of Child Development, a…

This study used a genetically controlled design to examine the direction and the magnitude of effects in the over-time associations between perceived relationship quality with mothers and adolescent maladjustment (i.e., depressive symptoms and delinquency). A total of 163 monozygotic (MZ) twins pairs (85 female pairs, 78 male pairs) completed…

In order to prepare students for adulthood and responsible citizenship, most high schools offer extracurricular activities designed to facilitate the learning of a wide range of competencies. The purpose of this study was to examine how participation in a single or a combination of extracurricular school activities for high school students may…

It is important to account for timing of puberty when studying the adolescent brain and cognition. The use of classical methods for assessing pubertal status may not be feasible in some studies, especially in male adolescents. Using data from a sample of 478 males from a longitudinal birth cohort, we describe the calculations of three independent…

Most research on mental health in individuals with autism spectrum disorder (ASD) and intellectual disability (ID) has focused on deficits. We examined individual (i.e., sociocommunicative skills, adaptive behavior, functional cognitive skills) and contextual (i.e., home, school, and community participation) correlates of thriving in 330 youth…

The causal factors associated with increases in depressive symptoms among adolescent girls remain an area of theoretical debate, and the limited research considering a hormonal influence has provided mixed results. The goal of the present study was to test a set of longitudinal associations, that, if found, would provide support for a hormonal…

Trajectories in bullying through adolescence were studied along with individual, family, and peer relationship factors. At the outset, participants' ages ranged from 10 to 14; 74% identified as European Canadian with the remainder from diverse backgrounds. With 8 waves of data over 7 years, 871 students (466 girls and 405 boys) were studied to…

Objectives: To longitudinally describe prosocial behaviour development from childhood to adolescence, using multiple informants within Canadian and Italian samples. Method: Participants in Study 1 were 1037 boys from low socioeconomic status (SES) areas in Montreal, Canada, for whom yearly teacher and mother reports were obtained between the ages…