Abstract:  Most previous studies have oversimplified the relationships among constructs. Researchers usually propose and test linear relations based on the assumption that “more is better”. Recently, along with the deepening of research, the perspective of too-much-of-a-good-thing effect (TMGT effect), i.e. the inverse U relation, has aroused more attention. By reviewing 44 research in organizational behavior field in recent five years, we identify four types of research topics, including positive feelings and thoughts at work, stable individual characteristics, characteristics of work and task, and group composition. We then identify two types of explanation mechanisms, which are summarized as “additive benefit and cost” and “interactive motivation and ability/opportunity”. In addition, we put forward that the moderation effect can be based on the change of single or dual mechanisms. We then discuss several suggestions for future research: (1) Diversify research topics and expand research levels; (2) Clarify the influencing mechanism behind TMGT effect; (3) Explore the threshold points based on the contextual factors; (4) Explicate the theoretical underpinnings of TMGT effect; (5) Improve sampling process and research design.

Key words: Too-much-of-a-good-thing effect, inverted U-shaped relationship, mechanisms, moderation effect