Introduction:
Leader expressions of gratitude toward subordinates represent a fundamental interpersonal dynamic within organizations and are often associated with improved employee attitudes and behaviors. Conceptually, such expressions reflect verbal signals through which leaders convey appreciation and recognition of employees' contributions. Although commonly regarded as an inherently positive signal, emerging evidence indicates that such expressions may elicit more complex responses. Some employees respond with positive emotions that enhance work engagement, whereas others may experience negative emotions that undermine it.


Purpose:
The present study investigates whether both positive and negative emotions operate simultaneously as mediators in the relationship between leader gratitude expression and follower work engagement, and whether employee pay satisfaction serves as a critical moderator shaping these effects.


Method:
We adopted a multi-source, multi-wave research design with data collected at two time points. The final sample comprised 199 leader-follower dyads nested within 76 work teams across 43 companies in Taiwan.


Results:
Results revealed that leader gratitude expression was positively related to followers' positive emotions and negatively related to their negative emotions. Both emotions mediated the relationship between leader gratitude expression and work engagement, although the indirect effect through positive emotions was substantially stronger. Pay satisfaction moderated these relationships by strengthening the link between leader gratitude expression and positive emotions and weakening the link with negative emotions. Moreover, analyses of conditional indirect effects showed that the indirect pathway through negative emotions emerged only when pay satisfaction was relatively low; when pay satisfaction was relatively high, the negative emotional pathway became nonsignificant.


Conclusions:
Overall, this study demonstrates that leader gratitude expression can activate dual emotional mechanisms, highlights the stronger role of positive emotions, and identifies pay satisfaction as a boundary condition that constrains the negative pathway. These findings advance theory on workplace gratitude and guide leaders in fostering engagement through context-sensitive appreciation.