Leaders and Introversion: Despite the Harvard view that extroverts make the best leaders, many CEOs are introverted. Jim Collins (in Good to Great) described best (level 5) leaders of the late 20th century as humble, not flashy personalities—leaders who build organizations, not their own egos. Extroverted leaders get better results (16% more) from passive workers. Introverted leaders get better results (14% more) from active workers. However, Wharton professor Adam Grant suggests that extroverts should dial it back in general, himself included.