Sour grapes: how coworker-targeted leader gratitude expressions shape witness deprivation and negative reactions

Purpose Expressing gratitude is a common organizational practice through which leaders publicly acknowledge employees' contributions. Prior research has mostly focused on its positive effects, particularly how witnessing such expressions strengthens observers' relational bonds and prosocial behavior. Yet, existing studies have overlooked the possibility that coworker-targeted leader gratitude expressions can threaten witnesses' sense of self-completeness and trigger negative responses. Drawing on symbolic self-completion theory, this study examines how such an expression elicits witnesses' relative deprivation. We further investigate how this reaction leads to self-symbolizing behaviors and how the boundary condition may mitigate these effects. Design/methodology/approach We tested the model in two studies: a 3-wave multisource survey (N = 320) and a scenario-based experiment (N = 246). Analyses included path analysis and a Johnson–Neyman plot with bootstrapped tests of conditional indirect effects. Findings Coworker-targeted leader gratitude expression was positively related to witnesses' relative deprivation, which predicted greater expediency and self-promotion. Mediation analyses confirmed that relative deprivation transmitted this effect to both outcomes. Moderated mediation analyses revealed that the indirect effect was weaker at higher levels of leader–member exchange (LMX). Originality/value This study identifies the negative witness effects of observing leaders' gratitude toward coworkers by showing that such expressions can threaten witnesses' self-completeness. It uncovers a compensatory process in which witnesses engage in expediency and self-promotion to restore self-completeness. It also identifies LMX as a key boundary condition that mitigates these indirect effects.