Revisiting leader–member exchange: a review through the lens of the “too much of a good thing” effect

Objectives This review reexamines the widely accepted belief that high-quality leader-member exchange (LMX) relationships are uniformly beneficial. Methods Based on the “too much of a good thing” framework, this study systematically reviews new empirical evidence suggesting that excessively high LMX may yield diminishing returns and negative outcomes. Results This review examines the unique and important contributions that high LMX relationships bring to LMX research. It highlights the emotional costs underlying non-linear patterns and presents an integrated Resource-Emotion-Motivation (REM) theoretical framework. Additionally, it discusses methodological aspects to better capture the dynamic relational process. Conclusion Finally, based on the reviewed papers, we present the academic and practical implications for future research. This review contributes to broadening the understanding of LMX dynamics.