The role of teacher-student relationships in mediating the impact of peer relationships and grit on student engagement

Student engagement is a key predictor of academic success in EFL contexts, yet a network of interpersonal and intrapersonal factors shapes it. Among these, peer relationships, grit, and the teacher-student relationship are increasingly recognized as central to explaining why some students participate more actively and persist in language learning than others, particularly in Chinese EFL classrooms. This study investigates how peer relationships and grit are associated with student engagement in Chinese EFL learning, with a specific focus on the mediating role of the teacher-student relationship. It examines (a) the direct effects of peer relationships and grit on the teacher-student relationship, (b) the direct effect of the teacher-student relationship on student engagement, and (c) whether the teacher-student relationship mediates the links between peer relationships and student engagement. Participants were 486 Chinese EFL students who completed a questionnaire battery measuring peer relationships, grit, teacher-student relationships, and student engagement. Confirmatory factor analysis (CFA) was used to validate the measurement model, and structural equation modeling (SEM) was employed to test the hypothesized direct and indirect paths among the constructs. SEM analysis revealed that both peer relationships (beta = 0.418, p < 0.001$) and grit β = 0.396, p < 0.001) exerted significant positive effects on the teacher-student relationship. In turn, the teacher-student relationship significantly predicted student engagement (beta = 0.567, p < 0.001). Mediation analyses demonstrated that the teacher-student relationship fully mediates the link between peer relationships and student engagement, while it partially mediates the relationship between grit and student engagement. Theoretically, these findings position the teacher-student relationship as the primary conduit through which peer support and personal grit are translated into classroom engagement. This extends social capital theory by demonstrating that intrapersonal and interpersonal resources are not disparate drivers of engagement, but are channeled through the quality of instructor-student rapport. These results suggest that for educators and policymakers in the Chinese EFL context, fostering high-quality teacher-student relationships is the most effective strategy for amplifying the benefits of peer support and student grit.