Antisocial Behavior Trajectories and Social Victimization Within and Between School Years in Early Adolescence

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 6^th grade, but beginning in 7^th grade for boys and 8^th 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.