| Abstract: | Using longitudinal data spanning early elementary through middle school, aggression behavior trajectory groups were identified for boys and girls. Early elementary school predictors of trajectory group membership were examined as well as whether trajectory group predicted physical aggression, covert delinquency, and substance use in 9th grade. Semiparametric group modeling identified aggression behavior trajectory groups. We identified four aggression trajectory groups for both genders described as “not involved,” “low,” “moderate,” and “high.” Attention problems, family conflict, and low school commitment and attachment were predictors of membership in higher aggression groups for both boys and girls. Low family involvement and low parental education predicted membership in higher aggression groups for boys; while depression, low‐income status, and having a single parent predicted higher aggression group membership for girls. For both boys and girls, few risk predictors distinguished between the moderate and high aggression trajectories except that low school commitment and having a teen mother were significant predictors of being in the high group for girls, and low parental education and income were significant predictors of being in the high group for boys. Membership in the higher aggression trajectory groups predicted involvement in violent behaviors, covert delinquency, and substance use in 9th grade. Findings suggest that children who display an early trajectory of high levels of aggressive behavior are more likely to continue involvement in later problem behaviors. Second‐grade predictors suggest commonality of risk across genders and provide evidence of modifiable targets for preventive interventions. Aggr. Behav. 32:1–15. 2006. © 2006 Wiley‐Liss, Inc. |
