Fig. 1: Research hypothesis model.

Hypothesis 1 (H1): an enhanced teacher–student relationship is associated with higher levels of moral sensitivity in adolescents. Hypothesis 2 (H2): perceived social support mediates the relationship between teacher and student relationship and adolescent moral sensitivity. Hypothesis 3 (H3): moral identity mediates the relationship between teacher and student relationship and adolescent moral sensitivity. Hypothesis 4 (H4): perceived social support and moral identity exhibit a chain mediating effect in the relationship between teacher and student relationship and adolescent moral sensitivity. Hypothesis 5 (H5): problematic social media use attenuates the positive impact of the teacher–student relationship on moral sensitivity among adolescents.