Gene–environment interplay linking friends’ antisociality with different developmental trajectories of antisocial behavior during adolescence.

This study investigated gene-environment correlations and interactions underlying the association between distinct developmental trajectories of adolescents' antisocial behavior and their friends' antisociality. Participants were 398 twin pairs (53% girls; 87% European descent) followed from age 13 to 19 years. Self-reported antisocial behavior was obtained from the twins and from their friends. Latent class growth modeling identified three antisocial behavior trajectories: nonantisocial, stable-low, and persistent-high. Biometric modeling revealed significant genetic influence on the probabilities of following either the nonantisocial or the persistent-high antisocial behavior trajectory. In contrast, the probability of following the stable-low trajectory was almost entirely explained by environmental influences. All three trajectories were correlated with friends' antisociality and these correlations were entirely explained by shared underlying environmental-not genetic-pathways. Moreover, friends' antisociality moderated the relative influence of genetic factors on the probability of following the persistent-high trajectory, as well as the relative influence of environmental factors on the probability of following the stable-low trajectory. The discussion stresses the importance of distinguishing distinct developmental trajectories of antisocial behavior during adolescence and the differential moderating role played by friends' antisociality. (PsycInfo Database Record (c) 2025 APA, all rights reserved).