The popular press and consultants often advocate for leader humor, emphasizing its potential benefits, such as enhancing leader-member exchange (LMX). However, existing literature provides limited and questionable support for the causal effect of leader humor on LMX, especially during the initial interactions between leaders and subordinates, or after newcomers enter the organization. Drawing upon social exchange theory and adaptation theory, we take the first attempt to address this issue by collecting data from two samples of newcomers who have recently joined an organization using longitudinal designs (Study 1 N = 181, three waves; Study 2 N = 196, four waves). Across both studies, the results of latent change score modeling indicated that (1) leader humor at Time n-1 was positively related to an increase in LMX between a leader and a newcomer from Time n-1 to Time n; (2) LMX between a leader and a newcomer at Time n-1 was positively related to an increase in leader humor from Time n-1 to Time n; (3) the influence of LMX on subsequent changes in leader humor was stronger than the reverse effect of leader humor (i.e., asymmetric reciprocity), suggesting that LMX is the dominant cause; and (4) the dynamic, mutually reinforcing relationship between leader humor and LMX remained consistent over time. Our findings challenge previous literature which has largely conceptualized leader humor as a unidirectional cause of LMX. We discuss these findings in terms of their theoretical and practical implications, as well as promising directions for future research.
