All of the stuff written about leadership has validity, and surely PMs can take a lot from it. But the problem is that most of it is a little too populist and all-inclusive, and lacks depth and substance.
To get closer to the essence of leadership, more digging is necessary. The bestsellers on the subject deliver the prescriptions and formulas of leadership, but there are also theories that are never homogenized into bestselling how-to books. Two worth mentioning are the Leadership Potential Equation and the Path-Goal Model.
In 1954, personality assessment expert Raymond Cattell developed the Leadership Potential equation, which was based on a study of military leaders. It is still used to determine the traits of effective leaders. Cattell sighted many traits mentioned by former GE superstar CEO Jack Welch and Antony Bell, author of Great Leadership: What It Is and What It Takes in a Complex World.
But he also mentioned additional traits that make a good leader. They include:
Emotional stability. Good leaders must be able to tolerate frustration and stress. Overall, they must be well-adjusted and have the psychological maturity to deal with anything they are required to face.
Assertive. Assertive in their thinking style as well as their attitude.