School-based music and extracurricular engagement as pathways to adolescent learning and wellbeing: mediating roles of self-regulation and school climate.

Introduction: Music and other creative activities are often recommended as affordable ways to support adolescent development, yet large-scale evidence on the psychological correlates linking such engagement to learning and wellbeing remains limited, especially in high-achieving East Asian systems. Using PISA 2018 data from the four Chinese economies of Beijing, Shanghai, Jiangsu and Zhejiang (B-S-J-Z), this study examines whether self-regulation and school climate statistically account for the associations between two engagement indicators and two outcomes. The engagement indicators are school-reported creative and musical provision (e.g., whether the school offers a band, orchestra or choir) and the availability of musical and cultural resources at home (musical instruments; books on art, music or design); both index opportunity and exposure rather than measured participation. Outcomes are academic achievement and subjective wellbeing. Methods: The analytic sample comprised 12,058 15-year-old students in 361 schools (weighted population ≈ 992,302). A structural equation model with latent mediators and outcomes was estimated via full-information maximum likelihood, complemented by a weighted, plausible-value-pooled regression-based mediation analysis with bias-corrected bootstrap confidence intervals, a school-clustered bootstrap accounting for the nested design, and a gradient-boosting model for triangulation. Given the cross-sectional data, results are reported as associations, not causal effects. Results: School-reported provision was associated with achievement directly, with no statistical mediation by self-regulation or school climate. Home musical and cultural resources were associated with both outcomes indirectly-through self-regulation and, to a smaller degree, school climate-and for wellbeing the indirect association exceeded the direct one. Self-regulation was the strongest correlate of wellbeing across all methods, though this association is inflated by conceptual overlap with wellbeing and is interpreted with caution. Discussion: Musical and creative engagement is associated with adolescent outcomes through different statistical routes depending on where the engagement is situated, and self-regulatory capacity and supportive school relationships are central correlates of wellbeing. Findings are specific to B-S-J-Z and are not generalised to China as a whole. Implications for curriculum policy, measurement and future longitudinal research are discussed.