Willpower

power of resolution is constant, he explains to her, and warns of what happens when it becomes frail: “Something will be done that we will not.” Sure enough, Cressida falls for a Greek warrior.
    When Troilus speaks of the “changeful potency” of willpower, he’s describing the sort of fluctuations observed in the students tempted by the cookies. After this concept was identified in the radish study and other experiments, it made immediate sense to clinical psychologists like Don Baucom, a veteran marital therapist in Chapel Hill, North Carolina. He said the Baumeister research crystallized something that he had sensed in his practice for years but never fully understood. He’d seen many marriages suffer because the two-career couples fought over seemingly trivial issues every evening. He sometimes advised them to go home from work early, which might sound like odd advice—why give them more time to fight with each other? But he suspected that the long hours at work were draining them. When they got home after a long, hard day, they had nothing left to help them overlook their partner’s annoying habits, or to be kind and considerate out of the blue, or to hold their tongue when their partner said something that made them want to respond in a mean, sarcastic manner. Baucom recognized that they needed to leave work while they still had some energy. He saw why marriages were going bad just when stress at work was at its worst: People were using up all their willpower on the job. They gave at the office—and their home suffered the consequences.
    After the radish experiment, similar results were observed over and over again in different groups of subjects. Researchers looked for more complex emotional effects and for other ways to measure them, like observing people’s physical stamina. A sustained exercise like running a marathon takes more than just conditioning: No matter how fit you are, at some point your body wants to rest, and your mind has to tell it to run, run, run. Similarly, it takes more than just physical strength to grip a hand exerciser and keep squeezing it against the force of the spring. After a short time, the hand grows tired and then gradually starts to feel muscle pain. The natural impulse is to relax, but you can will yourself to keep squeezing—unless your mind has been too busy suppressing other feelings, as in an experiment involving a sad Italian film.
    Before watching the movie, the subjects were told that their facial expressions would be recorded by a camera as they watched the movie. Some people were asked to suppress their feelings and show no emotions. Others were asked to amplify their emotional reactions so that their facial expressions would reveal their feelings. A third group, the control condition, got to watch the movie normally.
    Everyone then watched an excerpt from the movie Mondo Cane (“A Dog’s World”), a documentary about the effects of nuclear waste on wildlife. One memorable sequence showed giant sea turtles losing their sense of direction, wandering into the desert, and pathetically dying as they flapped their flippers aimlessly and feebly, unable to find the sea. It was unquestionably a tearjerker, but not everyone was allowed to cry. Some remained stoic, as instructed; some deliberately let the waterworks flow as much as possible. Afterward they all took the stamina test by squeezing the hand exerciser, and researchers compared the results.
    The movie had no effect on the stamina of the control group: The people squeezed the handles just as long as they had in a test before the film. But the two other groups quit much sooner, and it didn’t matter whether they’d been suppressing their feelings or venting their grief over the poor turtles. Either way, the effort to control their emotional reactions depleted their willpower. Faking it didn’t come free.
    Neither did a classic mental exercise: the white bear challenge. The white bear has been something of a mascot for psychologists ever since Dan Wegner heard the legend about how the young Tolstoy—or, depending on the version, the young Dostoyevsky—bet that his younger brother couldn’t go five minutes without thinking about a white bear. The brother had to pay up, having made a disconcerting discovery about human mental powers. We like to think we control our thoughts, but we don’t. First-time meditators are typically shocked at how their minds wander over and over, despite earnest attempts