Just how multi-level is leadership research? A document co-citation analysis 1980-2013 on leadership constructs and outcomes

The use of multi-level theories and methodologies in leadership has gained momentum in recent years. However, the leadership field still suffers from a fragmented and unclear evolution and practice of multi-level approaches. The questions of how and to what extent multi-level research has evolved in both leadership phenomena and leadership outcomes, and which informal research networks drove this evolution, remain vastly unexplored. In this study, the extent of literature published between 1980 and 2013 is analyzed using a document co-citation analysis and invisible colleges' framework. This allows us to map the evolution of the multi-level intellectual structure of the leadership field. Specifically, we identify a number of distinct colleges - their conceptualization of leadership and outcomes - and trace their evolution paths over thirty years. We find a considerable fragmentation of the field, with the usage of multi-level leadership conceptualization mostly embraced by more peripheral clusters. Finally we discuss implications for further research with regard to a set of distinct trajectories for the future evolution of multi-level approaches in the leadership domain.