Non-suicidal self-injury (NSSI) is a significant public health concern, with severely impacts for adolescent mental health. As awareness of the harmful effects of NSSI grows, there is an increasing emphasis on understanding the underlying mechanisms in this age group. This study explores how internalizing and externalizing issues related to…

Problematic internet use (PIU) has become a noticeable issue among adolescents, which negatively affects their physical and mental health. Previous research has noted the protective role of school climate in reducing PIU, but the underlying mechanisms need to be further explored. Based on the ecological systems theory, this study focused on the…

This preregistered, longitudinal study examined how much adolescents value and integrate their parents' and peers' attitudes into their own attitudes from early to middle adolescence. Across three waves, participants (N = 172, 91 female, 11-16 years across three waves; 439 data points) decided whether to pay money to learn their parents' or peers'…

To identify factors in adolescence that predict the onset of sexual violence in adolescence and young adulthood. Data were analyzed from six survey waves of the longitudinal Growing up with Media Study (2008-2018) conducted in the USA. Participants were 778 youth 13-18 years old at baseline, who completed online surveys assessing sexual violence…

Cyberbullying perpetration has become an international public health concern among adolescents. Based on the general aggression model, the present study sought to examine whether deviant peer affiliation was significantly related to adolescents' cyberbullying perpetration, and whether moral disengagement mediated this association and self-control…

Using alcohol, cigarettes, and marijuana during adolescence is associated with risks, yet there is no single cause for adolescent substance use. The etiology of substance use develops over time, across multiple levels of influence. Informed by developmental perspectives, in this review, we provide an overview of biological (e.g., genetic,…

This study examined how peer norms condition the effect of romantic involvement on adolescents' externalizing and internalizing problem behaviors. We hypothesized that, as a result of social control and social learning, adolescents who start a romantic relationship report more problem behavior when romantic involvement was not normative behavior…

The present study aims to investigate whether support from a friend protects against the negative effects of ethnic harassment on engagement in delinquent and violent behaviors among immigrant adolescents in Sweden (n = 365; X = 13.93, SD = 0.80). We found that when ethnically harassed immigrant adolescents received friend support, they were less…

The aim of the current study was to investigate the relationship between adolescents' social support, their internalising and externalising behaviour problems, and their alcohol consumption. Adolescents attending Grade 7-10 (N = 329), answered questionnaires regarding their perceived social support (from parents, teachers, classmates, and…

Although research has demonstrated that both parents and peers influence adolescent development, it is not clear whether these relationships also serve as contexts for emotion socialization. In the current longitudinal study, we investigated whether maternal and peer emotion socialization were related to adolescent girls' daily emotions, emotion…

The current study explored early adolescent child-level predictors (physical aggression, impulsivity, empathy) and contextual-level predictors (peer deviance, neighborhood dangerousness) of violent and nonviolent antisocial behavior (AB) in late adolescence. Additionally, we tested the moderating role of rejecting parenting on these associations…

This study estimates peer effects in diverse friendship networks by friend types. Evidence from friendship networks for 57,351 U.S. high school adolescents demonstrates that adolescents are more likely to make friends with someone of the same immigrant status or ethnicity ('similar friends') than those with different backgrounds ('dissimilar…

This study examined age-related changes in friend similarity on delinquency to determine whether deviant behavior homophily peaks during mid-adolescence. A community sample of 1,663 male and 1,826 female Swedish youth from Grade 5 (M = 11.21 years) to Grade 10 (M = 16.25 years) provided self-reports of delinquency. Friendships were identified from…

Adolescence is a very complex period. Various teen problems haunt when they grow up to become adults. The same teenagers successfully face the challenges of their development so that they are free from a variety of risky behaviors. However, some of them also smoke, consume alcohol, have free sex, commit violence, and use drugs. This research is a…

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…