Co-development of aggression in elementary school children: The predictive roles of victimization experiences

Aggression among peers is a common and serious problem in school-age children. Physical, relational, and cyber aggression often occur simultaneously but may exhibit heterogeneous developmental patterns. We aimed to identify heterogeneous co-developmental patterns of physical, relational, and cyber peer aggression and to investigate the contributions of victimization experiences to co-developmental trajectories. Participants were 2869 elementary school students (56.2% boys), initially in fourth grade (M_age  = 10.51 years) in China. Longitudinal data on peer aggression were collected from participants semiannually for 2 years. Data on victimization experiences were collected in the initial measurement wave. Parallel process latent curve growth modeling produced four co-developmental trajectories of peer aggression: High Desisting group, Moderate-Increasing group, Moderate-Physical and Relational Aggression group, and Low Stable group. Multivariate logistic regression analyses revealed that childhood emotional abuse, psychological maltreatment by teachers, as well as physical peer victimization, and cyber peer victimization, served as risk factors for severe co-developmental trajectories. The findings highlight the co-development of physical, relational, and cyber aggression. The identification of risk factors for co-developmental trajectories points to the need for continued monitoring and protection from ongoing victimization experiences in the family and school settings to prevent or ameliorate aggressive behavior.