Stuttering, or stammering (the terms are interchangeable clinically), occurs four times more frequently in males and ranges from mild hesitation in speech to severe disability. Hot irons were applied to stutterers' lips in the Middle Ages, and in the mid-19th century, risky tongue operations were performed in failed attempts to effect a cure. Bobrick discusses famous stutterers Charles Darwin, Henry James, Winston Churchill, and Jimmy Stewart, and he describes the adverse impact of their condition on their lives. In this century, psychological trauma has often been cited as the cause of stuttering, but recent evidence points to a genetic disorder involving a disturbed auditory function. Therapeutic practices differ, but the author credits a voice feedback system with bringing his condition under control.