In the Harvard Business Review "10 Must Reads: On Emotional Intelligence", Daniel Goleman writes about what makes a good leader. He concludes that there are three crucial ingredients: technical skill, IQ, and emotional intelligence.
Goleman writes that although technical skill and IQ matter, they are simply the entry requirements for a leadership position. Emotional intelligence is the most crucial ingredient. "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."
When Goleman calculated the ratio of technical skills, IQ, and emotional intelligence, emotional intelligence proved to be twice as important as the others.