Offline social and civic engagement as an ecological correlate of adolescent internet addiction: multilevel evidence from Chinese adolescents

Internet addiction (IA) has been a growing mental-health concern during adolescence. Although prior research has emphasized individual and family-related risk factors, less attention has been given to how adolescents’ everyday offline social environments relate to digital well-being. This study examined whether offline social and civic engagement (OSCE) is associated with adolescent IA at both individual and classroom-context levels and whether socio-emotional competence (SEC) helped explain this relationship. Using cross-sectional survey data collected in Spring 2025, we analyzed data from 7,121 secondary school students nested within 329 classrooms across five regions in China. Multilevel modeling was used to examine associations between OSCE, SEC, and IA while accounting for classroom clustering. Machine-learning analyses using accumulated local effects (ALE) plots were conducted to explore nonlinear and heterogeneous patterns in the OSCE–IA association across academic pressure, educational aspiration, and parent–child relationship quality. Higher OSCE was associated with lower IA at both the individual and classroom levels. SEC partly explained the association between OSCE and IA at the within-class level. Classroom OSCE climate was also negatively associated with IA, suggesting that broader engagement climates may be associated with adolescents’ digital behaviors beyond individual participation alone. Machine-learning analyses further revealed nonlinear patterns in the OSCE–IA association across academic and family contexts, with stronger negative associations observed under conditions of higher academic pressure and more supportive parent–child relationships. The findings support an ecological perspective on adolescent digital well-being in which offline participation contexts and socio-emotional competencies are associated with lower problematic internet use. Structured offline social and civic engagement may represent an important social-contextual correlate of healthier digital engagement among adolescents.