An accelerated longitudinal research design was used to examine heterogeneity in the developmental co-occurrence of peer relational victimization and aggression and of peer overt victimization and aggression from age 4.5 to 10.5 years. Data were gathered from four cohorts of children in kindergarten to Grade 3 (N = 503) on six occasions across 2 years. Psychopathology, peer, and social–cognitive factors were examined as predictors of the joint trajectories. Sequential process latent growth mixture models identified four distinct subgroups for the relational trajectories (co-occurring increasing aggression, co-occurring increasing victimization, high chronic victimization, typical low risk) and four distinct subgroups for the overt trajectories (co-occurring decelerating aggression, high chronic victimization, moderate chronic victimization, typical low risk). Membership in the co-occurring trajectories was associated with psychopathology and membership in the chronic victimization trajectories was related to internalizing and social–cognitive problems but also peer likeability.
