Developmental trajectories of boys' delinquent group membership and facilitation of violent behaviors during adolescence

Abstract

Being part of a delinquent group has been shown to facilitate the expression of an individual's own delinquent propensities. However, this facilitation effect has not been investigated from a developmental perspective within a population heterogeneity model. Using a semiparametric mixture model with data from the Montreal Longitudinal Experimental Study, this article addresses important issues in the developmental trends of membership to delinquent groups. We explore how the rate of violent behaviors follows delinquent peer group trajectories and investigate a differential facilitation effect of delinquent peers on violence across multiple developmental pathways. Results suggest that 25% of males followed a childhood or an adolescence delinquent group affiliation trajectory. These two groups account for most of the violent acts assessed during adolescence. In addition, the rate of violent behaviors follows these developmental trajectories. Controlling for these delinquent group trajectories, we also found that being involved in a delinquent group at any specific time during adolescence is associated with an increased rate of violent behaviors, and that leaving these groups results in a decrease in violent behaviors. This facilitation effect appears homogeneous over time and across developmental trajectories. Results are discussed from a social interactional perspective.

Gang Membership: The Psychological Evidence

“…Research evidence is, however, not conclusive on which of the three models best describes pre and post gang delinquency levels, (see Lacourse et al, 2003, andHall et al, 2006). This may be due to the individual differences of gang members, which is acknowledged by Interactional theory when it notes that not all gang members are alike.…”

Understanding Mechanisms of Change in the Development of Antisocial Behavior: The Impact of a Universal Intervention

“…As a result, antisocial children progressively affiliate with similarly antisocial peers. Such an affiliation has been shown to lead to high levels of antisocial behavior and to juvenile delinquency (Lacourse, Nagin, Tremblay, Vitaro, & Claes, 2003;Patterson, Dishion, & Yoerger, 2000). A second negative consequence of this behavior is that children are placed at increased risk for the development of depressive problems (Fergusson, Wanner, Vitaro, Horwood, & Swain-Campbell, 2003).…”

Measuring Long Term Individual Trajectories of Offending Using Multiple Methods

“…Examples that use GTM to control for individual heterogeneity include Lacourse et al (2003) for gangs, Nagin et al (2003) for school failure and Laub et al (1998) and for marriage. In a related approach, researchers have used the groups from the GTM models to match similar individuals in order to assess the impact of various time-varying covariates on crime and delinquency (Haviland and Nagin 2005;Apel et al 2007;Nieuwbeerta et al 2009).…”