Heterogeneity in the Joint Trajectories of Bullying Victimization and Defending Behavior among Adolescents: The Role of Anti-Bullying Attitudes and Peer Status.

Evidence suggests intricate associations between bullying victimization and defending behavior. However, previous studies have predominantly used variable-centered approaches to examine associations between victimization and defending, whereas relatively few have examined heterogeneity in the joint longitudinal trajectories of these two behaviors. This study investigated the heterogeneous joint trajectories of victimization and defending behavior, as well as how these distinct trajectories related to anti-bullying attitude and peer status. A total of 2,772 Chinese adolescents (49.7% girls; MageT1 = 13.28 years, SD = 0.46) completed surveys across four waves spanning two years, with data collected at six-month intervals. Parallel-process Latent Class Growth Analysis identified a congruent trajectory group and three incongruent trajectory group: high victimization and low defending (7.8%), low victimization and high-aggressive defending (12.3%), low victimization and high-nonaggressive defending (29.1%), low victimization and low defending (50.8%); but no group reflected concurrently high levels of victimization and defending. Adolescents with stronger anti-bullying attitudes and higher peer status were more likely to defend peers and less likely to be victimized, whereas those with higher likeability alone showed limited defending despite similarly low victimization. These findings underscore the importance of capturing heterogeneous trajectories between victimization and defending behavior, and provide implications for developing intervention programs.