There are an almost infinite number of ways to study or think about the phenomenon of leadership. Some deal with the traits or personal qualities of leaders (in contrast to those of nonleaders), some deal with the skill sets of leaders, and other approaches examine the situations that elicit leadership. Approaches that focus on personal traits tend also to engage the question of how leaders are selected; approaches that focus on skills, on the other hand, tend to highlight the training of leaders; and those that feature the situational determinants of leadership focus on the specific tasks that leaders must master in order to lead. Some theories highlight leadership as the ability to execute tasks, to have the expertise to solve problems, while other theories focus on leadership as a set of interpersonal skills-the ability to influence people rather than work environments. And other theories ask not what constitutes leadership, but what are the characteristics that cause people to attribute leadership qualities to other people. Why do we think that some people are good leaders while others are not?