ABSTRACT
Antisocial behavior typically increases during early adolescence, but the possibility of seasonal variation has not been examined. In this study, trajectories of antisocial behavior were estimated for early adolescent boys and girls. Data were obtained from a 3-year longitudinal study of 11 middle schools in the western U.S. (n = 5,742), with assessments completed four times per academic year. Antisocial behavior increased steadily throughout 6th grade, but beginning in 7th grade for boys and 8th grade for girls, it declined during the school year. Significant increases between grades 6-7 and 7-8 were found for both genders. Trajectories varied by contextual and individual-level social victimization and gender. Implications for theoretical development and future studies are discussed.
ABSTRACT
A novel version of Snijders's stochastic actor-based modeling (SABM) framework is applied to model the diffusion of first alcohol use through middle school-wide longitudinal networks of early adolescents, aged approximately 11-14 years. Models couple a standard SABM for friendship network evolution with a proportional hazard model for first alcohol use. Meta-analysis of individual models for 12 schools found significant effects for friendship selection based on the same alcohol use status, and for an increased rate of onset to first use based on exposure to already-onset peers. Onset rate was greater at higher grades and among participants who spent more unsupervised time with friends. Neither selection nor exposure effects interacted with grade, adult supervision, or gender.
