Leadership is a fascinating subject for many people. The term conjures up a familiar scene of a powerful, heroic, triumphant individual with a group of followers returning home after winning a national championship or a war against the evil enemy. They all march through town surrounded by a crowd waving flags. Or an enthusiastic orator delivers an energetic speech, hands waving in the air, to thousands of people gathered in a plaza.

The widespread fascination with leadership may be because of the impact that leadership has on everyone's life. Stories of heroic leadership go back thousands of years: Moses delivering thousands of Hebrews from Egypt or Alexander the Great building a great empire. Why were certain leaders able to inspire and mobilize so many people, and how did they achieve what they achieved? There are so many questions to which we want answers, but many remain as puzzling...