In a Harvard Business Review article, Daniel Goleman writes about what makes a leader?
He writes that the most effective leaders are alike in one crucial way.
"They all have a high degree of what comes to be known as emotional intelligence. It's not that IQ and technical skills are irrelevant. They do matter, but mainly as threshold capabilities; that is, they are the entry-level requirements. But my research, along with other recent studies, clearly shows that emotional intelligence is the "sine qua non" of leadership.
Without it, a person can have the best training in the world, an incisive, analytical mind, and an endless supply of smart ideas, but he still won't make a great leader."
You can read the full article here.