Too much of a good thing: The impact of mentoring on innovation capacity among undergraduate students—Evidence from a provincial University in China

This study investigates the nonlinear relationship between faculty mentoring and undergraduate innovation capacity within a universal tutorial system. Drawing on survey data from 1066 students at a Chinese provincial university, and grounded in motivational synergy theory and self-determination theory, we examine an inverted U-shaped effect of mentoring frequency, with an estimated inflection point of 13.35 sessions per semester. Bootstrap-based conditional indirect effects suggest that this pattern is consistent with both extrinsic (mentor pressure, peer influence) and intrinsic (academic identity, self-efficacy) motivational pathways, with the indirect effects themselves shifting from positive to negative as mentoring intensifies. Furthermore, the curvilinear pattern is more pronounced under low mentor-student research alignment, in smaller meeting cohorts, and within STEM disciplines. The mentoring benefits concentrate among students with moderate innovation capacity, suggesting an “expanding the middle” effect. These findings provide convergent evidence that the synergy-versus-crowding-out logic operates across mentoring intensity, motivational pathways, and student capacity, offering a more differentiated and mechanism-based understanding of how faculty mentoring shapes undergraduate innovation.