Leadership
The explanation of leadership is neither absolute, nor yet approved upon. For most people leadership is one of those things that they can't portray, but they know it when they see it. For now, we're going to use the definition of leadership as "the aptitude to influence people or groups on the way to one or more goals." From this definition, it seems that leadership belongs in the next segment: at the group level of analysis. However, the history of leadership began with a very personality level look at what constitute a leader. So that's where we'll start as well. In investigation there are three main types of theory: (1) behavioral theories; (2) trait theories; and (3) contingency theories.