A central theme of research on human development and psychopathology is whether a therapeutic intervention or a turning-point event, such as a family break-up, alters the trajectory of the behavior under study. This article describes and applies a method for using observational longitudinal data to make more transparent causal inferences about the…

Because youth gangs tend to cluster in disadvantaged neighborhoods, adolescents living in such neighborhoods are more likely to encounter opportunities to join youth gangs. However, in the face of these opportunities, not all adolescents respond in the same manner. Those with preexisting psychopathic tendencies might be especially likely to join.…

Background: Different developmental courses have been postulated for proactive and reactive aggression. Objective: Investigated the developmental course of proactive and reactive aggression in a large sample of adolescent boys from low socioeconomic areas. Method: A dual group-based joint trajectory method was used to identify distinct…

Examined stability of gang membership in early adolescence, concurrent behaviors, family characteristics, friendships, and school attitudes of stable and unstable gang and nongang members. Found that stable gang members, compared to nongang members, had higher teacher ratings of fighting behavior, hyperactivity, inattention and oppositional…

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)…