Daniel Goleman, in The Essentials: An Introduction to the most enduring ideas on management from Harvard Business Review, wrote:
I have found … that the most effective leaders are alike in one crucial way: They all have a high degree of what has come to be known as emotional intelligence (p 63).
Goleman identified five components of emotional intelligence. They are:
Self-awareness
Self-regulation
Motivation
Empathy
Social skill
If you are interested in reading learning more, these components are developed with sufficient detail in the chapter (What Makes a Leader?) within the book (The Essentials). This is but one article among many worthy of reading.