Abstract: The development and control of childhood aggression have been among topics that received the most attentions from researchers for more than half a century, and in research on aggression, exploration of the correlated risk factors and mechanisms of aggression is one of the most important tasks. Research indicated that peer rejection and peer victimization, forms of peer relationship adversities, were predictive of children’s aggression. There are correlations between peer rejection and victimization, so in investigating associations between peer relationship adversities and children’s aggression, it is important to include both the two forms of peer relationship adversities in the statistical models so that the unique associations may be tested. There are physical and relational forms in both aggression and peer victimization, and recent theoretical perspectives recognize the specificity of associations between certain types of peer experience and children’s adjustment. Accordingly, research on the associations between peer victimization and aggression should take both of the two forms of victimization and aggression into consideration, so as to examine whether there are type specificity in associations between victimization and aggression. As there are associations between peer relationship adversities and children’s aggression, then, we would like to ask which factors and mechanisms are involved in these associations. According to the social information processing (SIP) model, not only deficits in SIP steps but also social knowledge play a role in the development of children’s aggression. The existing studies have examined the mediating roles of SIP steps in the association between peer rejection or victimization and children’s aggression, but little is known about the possibly mediating role of children’s social knowledge such as the self – peer representation in the association between peer relationship adversity and aggression. The current study was to explore the association between both types of peer relationship adversity (pee rejection and victimization) and the development of children’s aggression, the mediating roles of children’s self – peer representation in the association, and the gender differences in the associations mentioned above. 1806 children of grade 5 (mean age 11.27+0.36 years old) from 40 classes of 14 primary schools in Jinan, a city in mid-east China, were investigated. The participants finished a self-reported questionnaire on experience of peer victimization, the physical self-conception and social acceptance subscales of the Perceived Competence Scale for Children, and a peer belief inventory. Peer rejection was obtained through peer nomination, and physical aggression and relational aggression were assessed through peer rating. All of the measures showed good reliability. Significant correlations existed between the two forms of peer relationship adversity, children’s aggression, and self-conception and peer belief except for that between peer rejection and children’s physical self-conception. Latent structure equation modeling revealed significant prediction of peer rejection and relational victimization on children’s physical aggression and relational aggression, and significant prediction of physical victimization on physical aggression. Children’s physical self-conception, social self-conception and peer belief mediated the associations between peer rejection, peer victimization and aggression. These results indicated that, there was mainly a direct effect from peer rejection to both types of aggression, and specificity of associations between certain types of victimization and aggression.

Key words: peer rejection, peer victimization, aggression, self-conception, peer belief