Most violence begins in the second decade of life.
It also examines violence in relation to other risky behaviors that emerge in adolescence. The dynamics of youth violence are best understood from a developmental perspective, which recognizes that patterns of behavior change over the life course. Adolescence is a time of tumultuous change and vulnerability, which can include an increase in the frequency and means of expression of violence and other risky behaviors. Understanding when and under what circumstances violent behavior typically occurs helps researchers craft interventions that target those critical points in development. Our understanding of developmental patterns depends in large part on longitudinal studies, which track the same group of individuals over long periods of time, sometimes a decade or more.