Abstract
INTRODUCTION: This study explored how gratitude and mindfulness contribute to psychological wellbeing (PWB) among Chinese university students, using an explanatory sequential mixed-methods design to test a structural model and qualitatively examine the lived experiences behind the statistical pathways. METHODS: In the quantitative phase, 481 EFL students (61.9% female, M (age) = 20.34) completed validated measures of gratitude, mindfulness, optimism, and PWB, with data analyzed through Structural Equation Modeling (SEM). Subsequently, 18 participants from this sample were purposefully selected for semi-structured interviews, analyzed via reflexive thematic analysis. RESULTS: The SEM results showed a good model fit, confirming optimism as a robust mediator. Gratitude (β = 0.36) and mindfulness (β = 0.29) significantly predicted optimism, which strongly predicted PWB (β = 0.60). Bootstrapping revealed that optimism fully mediated the mindfulness-PWB link (indirect β = 0.17, p < 0.001; direct β = 0.06, p = 0.244) but only partially mediated the gratitude-PWB link (indirect β = 0.22, p < 0.001; direct β = 0.14, p = 0.021). Qualitative findings enriched these results, portraying optimism as an "agentic fuel" for eudaimonic action, with gratitude fostering it through "evidentiary reappraisal" and mindfulness through "cognitive decoupling." The direct effect of gratitude was attributed to its role as an immediate "in-the-moment social dividend," enhancing positive relations within PWB. DISCUSSION: These findings suggest that optimism is a key mechanism linking positive resources to wellbeing, though not exclusively. Mindfulness supports wellbeing by creating mental space for optimism, while gratitude operates dually, building optimism for future benefits and directly enhancing social-relational aspects of PWB in the present. Interventions should target these distinct mechanisms to optimize student wellbeing.