According to David McClelland and David Burnham, managers fall to three motivational groups: affiliative managers, managers motivated by the need to achieve, and institutional managers. People in the first group aim to increase their popularity rather than achieve their individual goals. Those in the second group desire to reach their goals and obtain their own recognitions, regardless of what people think of them. However, those in the third group are motivated by power. People in the third group are the most effective and productive. They realize that the fundament of leadership is building power through influence people.

But why are managers motivated most by power? A successful manager usually has a greater need to influence others than a need to achieve personal goal or a need to be liked. Managers are those who lead a team to achieve a team goal. This is why they do not have a strong need to achieve individual goal. In addition, a successful manager should be capable to arrange his subordinates’s work properly. They have to be responsible, focusing on the entire team rather than individual. Thus, those who are motivated by power are more influential.

article source:http://hbr.org/2003/01/power-is-the-great-motivator/ar/1