Study of outstanding leaders: they got the interviewer to laugh with them twice as often as average/less effective leaders; used humorous comments three times more frequently (e.g., once every 4 minutes); used humor to reduce stress and positively impact their interactions. (Goleman, Daniel, PhD, with Richard Boyatzis, and Annie Mckee. Primal Leadership. p 34-35. Boston: Harvard Business School Press, 2002.)