Individual differences as antecedents of leader behavior: Towards an understanding of multi-level outcomes

The leadership research on individual differences is going through a period of revival. However, due to the substantial number of variables in this area and the different knowledge bases they are associated with (e.g., psychology, endocrinology, genetics), the literature is also becoming highly fragmented as it grows. This fragmentation is preventing different literature streams from effectively communicating with each other and synthesizing the rapidly expanding body of knowledge. Consequently, the continued growth of the individual differences literature is at risk. Therefore, we believe that classifying the relevant literature streams and reviewing the key variables in those streams will be beneficial. We do so by organizing this review and research agenda of the leadership literature on individual differences around the recent model developed by Antonakis, Day, and Schyns (2012). In doing so, we hope to unify some of the future research efforts around a recent and recognized conceptual model, and in turn facilitate communication between these different streams of literature. Moreover, insights from this literature also allow us to propose additions and refinements to the model of Antonakis, Day, and Schyns (2012) that may help scholars by indicating other fruitful areas for future research on individual differences.