IQ versus EQ. What’s the difference? Which really matters for professional success? Historically, a lot of emphasis has been placed on the importance of IQ, also known as intelligence quotient, which essentially measures a person’s reasoning ability. While IQ has been found to be responsible for 10-25% of professional success, another attribute has been found to be far more important. EQ, or emotional intelligence, is the ability to sense, understand and effectively apply the