Abstract
OBJECTIVE: In the context of mobile internet use, adolescents' online engagement is increasingly intertwined with offline socialization. Although previous studies have revealed a negative association between internet addiction and social adaptation, they have often examined peer relationships and self-identity as separate mediators, lacking systematic validation of their sequential role. Guided by the Bioecological Model, this study examined the chain mediation of peer relationships and self-identity between internet addiction and adolescents' social adaptation, and further compared gender differences in the association between peer relationships and self-identity. METHODS: We conducted a cross-sectional study among 1,080 students from multiple middle schools in China. Standardized scales were used to assess internet addiction, peer relationships, self-identity, and social adaptation. Structural equation modeling and multigroup analysis were employed for statistical testing. RESULTS: Internet addiction was negatively associated with social adaptation. Peer relationships and self-identity jointly mediated this relationship in a sequential manner. Multigroup analysis indicated gender differences in the positive association between peer relationships and self-identity, showing a stronger effect among male students. CONCLUSION: Within the Bioecological Model, this study jointly rather than independently validated the mediating roles of peer relationships and self-identity, providing systematic evidence for the association between internet addiction and social adaptation. In practice, interventions should prioritize strengthening peer support and fostering its connection with self-identity and social adaptation, while paying appropriate attention to male adolescents.