My Teacher and Parents Make Me More Helpful Toward Others: The Sequential Mediating Roles of School Belonging and Prosocial Behavior in Adolescents’ Academic Achievement

Background/Objectives: This study used structural equation modeling (SEM) to examine the sequential mediating roles of school belonging and prosocial behavior in the effects of parent–adolescent and teacher–student relationships on adolescents’ academic achievement. Methods: Using a cross-sectional design, the study included 523 adolescents (61.6% female, 38.4% male) aged 13 to 19. Data were collected with the Mother–Adolescent Relationship Quality Scale, the Teacher–Student Relationship Quality Index, the School Belongingness Scale, and the Student Prosocial Behavior Scale, together with subjective (perceived achievement) and objective (school grades) indicators of academic achievement. Results: Both parent–adolescent (β = 0.25) and teacher–student (β = 0.44) relationships significantly predicted school belonging; school belonging significantly predicted prosocial behavior (β = 0.22); and prosocial behavior, in turn, significantly predicted academic achievement (β = 0.22). The direct effect of parent–adolescent relationships on academic achievement was significant (β = 0.26), whereas neither the direct effect of teacher–student relationships (β = 0.13) nor the direct effect of school belonging on academic achievement was significant. The indirect effects of both relational contexts on prosocial behavior via school belonging were significant, and school belonging predicted academic achievement indirectly through prosocial behavior; however, neither the total indirect effect of parent–adolescent relationships on academic achievement, nor its specific serial indirect effect through school belonging and prosocial behavior, reached statistical significance. The corresponding specific serial indirect effect for teacher–student relationships was statistically significant, although small in magnitude and not accompanied by a significant total indirect effect. Conclusions: These findings indicate that school belonging is more closely tied to socio-emotional processes than to academic achievement directly, and that the associations between relational contexts and academic achievement followed a differentiated rather than a uniform pattern: parent–adolescent relationships were linked to achievement primarily through a direct association, and their hypothesized distal indirect pathway to achievement via school belonging and prosocial behavior was not statistically supported. Teacher–student relationships, by contrast, showed no significant direct association with achievement, but the corresponding distal indirect pathway was statistically supported, although the effect was small and imprecisely estimated, underscoring the need for cautious interpretation of these relational mechanisms.