On the number and shape of developmental/life-course violence, aggression, and delinquency trajectories: A state-of-the-art review

Purpose: To comprehensively review the literature on the number and shape of latent group-based trajectories of violence, aggression, and delinquency. Materials and Methods: A systematic and exhaustive search of several academic databases (e.g., Criminal justice Abstracts, Web of Knowledge, EBSCO Host, Psychlnfo, PubMed) was conducted. Google Scholar searches were conducted to locate articles that are currently "in press." Results: This narrative meta-review identified 105 studies that used latent trajectory modeling to describe the number and shape of violence, aggression, and delinquency trajectories. The number of trajectory groups ranges from 2-7 groups. However, most studies report between 3 and 4 groups, loosely including life-course persistent or chronic offenders, a group of escalators or desistors, and one group that does not exhibit violent, aggressive, or delinquent behavior. Conclusions: There is substantial variability in the number and shape of trajectory groups across samples, measurement, developmental phase of the life-course captured, length of observation, and geographical context. However, the studies are largely consistent with Moffitt's taxonomy. Future research should extend trajectory modeling beyond description to examine theoretically relevant risk and protective factors for violence, aggression, and delinquency, investigate empirically relevant outcomes associated with violence, aggression, and delinquency, and focus on policy-relevant research. (C) 2012 Elsevier Ltd. All rights reserved.