John Tierney on His New Book Willpower: Rediscovering the Greatest Human Strength

Are you an impulsive marshmallow eater? Your success—or failure—in life may depend on how you answer that question, says New York Times science writer John Tierney. "The marshmallow test," explains Tierney, was an experiment "where 4-year-olds would be given a marshmallow. They were told they could eat it but if they waited 15 minutes they would get two marshmallows.…The kids who managed to resist the marshmallow did much better in school, did much better in life. That's what really kicked off the modern self-control movement." From our March issue, Tierney discusses his new book on the subject, Willpower: Rediscovering the Greatest Human Strength, with Managing Editor Katherine Mangu-Ward.