A systematic literature search was done in Google Scholar. The terms used in the search machine were “leadership”, “LMX”, “gender”, and “OCB”. The results were sorted by relevance and not filtered by publication date. The first step of analysis was simply reading the title. If the title seemed relevant to this review, the second step was to read the abstract. If this indicated the article would be of significance to the paper, the article was read in its entirety. Some papers referenced other papers, and these were not always read completely. However, some referenced information is included in the review. Apart from apparent (ir)relevance, no other inclusion or exclusion criteria were considered. Overall, 35 pieces of literature were included of which 19 were completely read.

Literature review

Leader-Member Exchange Theory

According to Graen and Uhl-Bien (1995), leadership research should not put its focus on the leader only. They argue that leadership consists of three domains: the leader, the follower, and their relationship. This taxonomy could be seen as the foundation of LMX theory, since the most differential aspect of the theory is the emphasis that is laid on the leader-follower dyadic relationship. LMX proposes that leaders do not treat all their followers in the same way. They split their followers into two groups: in groups and out groups. The followers that are categorized into the in groups are given more time and attention than those categorized into the out groups. Furthermore, the performance of in group members is often evaluated as higher than that of out group members, and in group members seem to be more satisfied with their LMX relationship compared to out group members (Varma & Stroh, 2001). Scholars suggest that leaders’ classification into in and out groups is mostly based on factors that are unrelated to performa