Being very good at solving problems is a fundamental characteristic of effective leaders in all fields. A meta-analysis of 151 studies found a positive relationship between intelligence and job performance of leaders in many different settings. The relationship is likely to be higher when the leader plays an active role in decision making and is not overly stressed. The researchers also found support for the old idea that intelligence contributes the most to leadership effectiveness when the leader is not vastly smarter than most group members.

Again, group members prefer that their leaders be smarter than the average group member even if the difference is not huge. Cognitive intelligence is all the more useful for leadership when it is supplemented by practical intelligence, the ability to solve everyday problems by using experience-based knowledge to adapt to and shape the environment. Practical intelligence is sometimes referred to as street smarts, and also includes wisdom. Recent evidence suggests that specific problem-solving skills, such as wisdom, are more closely related to leader performance than general intelligence.