LMX, organizational justice and performance: curvilinear relationships

Purpose Organizational research has long been dominated by the assumption that relationships between variables are linear, which can be overly simplistic or even misleading. This study proposes and tests a model in which subordinate organizational justice perceptions influence the linearity of the relationship between leader–member exchange (LMX) and subordinate task performance. Design/methodology/approach A time-lagged anonymous survey study was conducted in Romania on a sample consisting of 274 subordinates nested under 42 leaders from a wide range of work settings. Supervisors rated the performance of their direct reports, while subordinates rated LMX and justice perceptions. Findings Hierarchical linear modeling results revealed that the associations of LMX and LMX affect with task performance were best described by an inverted U shape when perceptions of supervisory interpersonal justice were high. Relationship strength was also affected. No such moderating effects were confirmed for other types of justice. We also found an unmoderated nonlinear effect of LMX-professional respect on task performance. Practical implications Results suggest that for supervisors who are perceived as fair in terms of interpersonal justice, a moderate level of LMX (especially LMX affect), slightly above the mean, maximizes subordinate task performance, while high LMX is preferable otherwise. Similarly, a moderate level of LMX professional respect seems optimal for performance. Originality/value The present paper challenges the linearity assumption for the established LMX–performance association, demonstrating that both the linearity and strength of the association may be influenced by justice. Second, results suggest that the too-much-of-a-good-thing effect may be the result of additive effects. Third, differential effects of LMX and justice dimensions are revealed.