Willpower

the prison sentences of felons appearing before weary judges. It influences the behavior of everyone, executive and nonexecutive, every day. Yet few people are even aware of it. When asked whether making decisions would deplete their willpower and make them vulnerable to temptation, most people say no. They don’t realize that decision fatigue helps explain why ordinarily sensible people get angry at their colleagues and families, splurge on clothes, buy junk food at the supermarket, and can’t resist the car dealer’s offer to rustproof their new sedan.
    This hazard was first identified at Baumeister’s lab by Jean Twenge, a postdoctoral student who took up self-control research at the same time that she was planning her wedding. As she read up on the lab’s previous experiments, like the one showing how self-control was depleted by the act of resisting chocolate chip cookies, she was reminded of a recent and quite draining personal experience: registering for wedding gifts, that odd tradition of enlisting a corporation to help with extorting gifts from family and friends. Although it’s ordinarily considered rude for anyone beyond the Santa Claus years to demand specific gifts, listing your wishes on a bridal registry has been rationalized as a social ritual that eases the stress on everyone. The guests don’t have to bother shopping; the couple doesn’t have to worry about ending up with thirty-seven soup tureens and no ladles. But that doesn’t mean it’s stress-free, as Twenge discovered on the evening that she and her fiancé sat down with the store’s wedding specialist to decide exactly what items to put on their registry. How ornate did they want their china to be? Which brand of knives? What kind of towels? Which color? Precisely how many threads per square inch of their sheets?
    “By the end,” Twenge told her colleagues in the lab, “you could have talked me into anything.” She thought the experience of having one’s willpower depleted must be something like the way she felt that evening. She and the other psychologists wondered how to test that idea. They remembered that a nearby department store was going out of business and holding a clearance sale, which made plenty of products affordable on the laboratory budget. The researchers went shopping and filled their car trunks with simple products—not exactly posh wedding gifts, but sufficiently appealing to college students.
    For the first experiment, participants were shown a table loaded with these products. They were told they would get to keep one at the end of the experiment. Then some of the students were told to make choices, which would supposedly determine which product they eventually received. They went through a series of choices, each time between two items. Would they prefer a pen or a candle? A vanillascented candle or an almond-scented one? A candle or a T-shirt? A black T-shirt or a red T-shirt? Meanwhile, a control group—call them the nondeciders—spent an equally long period of time contemplating all these same products without having to make any choices. They were asked just to rate their opinion of each product and report how often they had used such a product in the last six months. Afterward, everyone was given one of the classic tests of self-control: holding your hand in ice water for as long as you can. The water is uncomfortable and the impulse is to pull the hand out, so self-discipline is needed to keep the hand under water. It turned out that the deciders gave up significantly sooner than the nondeciders. Making all those choices had apparently sapped their willpower, and the effect showed up again in other decision-making exercises.
    In some experiments, students had to go through a college catalog and choose courses for themselves. In another experiment, designed to be immediately relevant to students enrolled in a psychology course, they had to make a series of choices about how they wanted their course to be taught for the remainder of the semester: which films to watch, how many quizzes to have. After making the choices, some students were given puzzles to solve. Some were told that they were about to take a math test that would be an important measure of their intelligence, and that they could improve their score if they spent fifteen minutes practicing for it—but in addition to being given practice materials for the test, they were left in a room with magazines and handheld video games as