Colleagues,
Antonakis, Day & Schyns (2012) in the latest issue of Leadership Quarterly defined the subject of "Individual Differences" (IDs): "Psychological or biological characteristic that exhibit four essential properties": (1) measurable, (2) vary across individuals, (3) stable, and (4) predict outcomes.
This definition is different and far more restrictive than the one I learned in the Psychology program at the University of Minnesota. We defined IDs to include genetic endowment, physical, chemical, electrical, and development characteristic of humans that were measurable in principle, may or may not be dynamic, and may in principle predict behavior in situations.
A less restrictive definition of IDs is need for today dynamic, complex, and cooperative task demands and their LMX team leadership.
George GraenLeadership-Motivated Excellence