In-role perceptions buffer the negative impact of low LMX on helping and enhance the positive impact of high LMX on voice.

In 2 field studies, we demonstrated that the relationship between leader-member exchange (LMX) and organizational citizenship behavior (OCB) is moderated by employee role perceptions--the extent to which employees view specific types of OCB as in-role behavior (IRB) versus extra-role behavior (ERB). In addition, we predicted and demonstrated that the form of these interactions differs on the basis of the type of OCB. For helping (aimed at the supervisor or the organization), results show a substitute effect in which viewing helping as IRB buffers the negative effect of low-quality LMX on helping. In contrast, for voice (aimed at the supervisor or the organization), results demonstrate an enhancer effect in which viewing voice as IRB amplifies the positive effect of high-quality LMX on voice. We discuss theoretical and practical implications with an emphasis on how conceptual differences in types of OCB influence the interactive effects of role perceptions on LMX-OCB relationships.