Genetic and contextual risks and developmental mechanisms underlying childhood aggression and young adult justice system involvement.

Aggressive behavior, shaped by genetics and environmental or contextual influences, is expressed differently across development and may lead to criminal justice involvement through arrests and incarceration for some individuals. This study examined the differential impacts of early childhood contextual risk and polygenic risk on a developmental cascade from middle childhood physical aggression and dysregulation to adolescent antisocial behavior, to criminal justice system involvement by age 19, and whether these risks were mitigated by random assignment to the Family Check-Up (FCU) prevention program. The sample included high-risk toddler (N = 731; Mage = 28.2 months, SD = 3.28; 49.5% female, 50% White, 28% Black, 13% Hispanic) and parent dyads involved in a randomized-controlled trial of the FCU and followed longitudinally across 11 waves from ages 2 to 19. Results supported a developmental cascade from middle childhood physical aggression (parent reported) to self-reported legal system involvement at age 19. Early cumulative contextual risk predicted arrests (b = 0.35, p = .001), while a risk tolerance polygenic score predicted self-reported adolescent antisocial behavior (b = 0.51, p = .005). Further, the FCU attenuated the genetic effects on antisocial behavior in adolescence. Findings highlight the value of early prevention for reducing the impact of genetic and contextual risk on rates of justice system involvement by young adulthood.