The Guardian's Jon Henley reviews Willpower: Rediscovering the Greatest Human Strength, a popular science/self-help book by Roy F Baumeister, "eminent American social psychology professor" and NYT science writer John Tierney. It sounds like a practical guide combined with a literature review on the lines of such excellent books as Daniel Gilbert's Stumbling on Happiness.
Henley describes the book as a good mix of science, practical advice, and clear writing, which is pretty much right up my street, as is the subject-matter: understanding why it's hard to get your brain to do what you want to do. "Willpower" is something of a catch-all term, but in general, it's the source of all my pleasures and many of my sorrows: it's the secret to regular writing and good health, but it's also the source of a fixity of purpose that sometimes blocks out other considerations.
Like a muscle, it can get tired if you overuse it. Exercising willpower, but also making decisions and choices and taking initiatives, all seem to draw on the same well of energy, Baumeister has established. In experiments, he found that straight after accomplishing a task that required them to restrain their impulses (saying no to chocolate biscuits, suppressing their emotions while watching a three-tissue weepy), students were far more likely to underperform at other willpower-related jobs such as squeezing a handgrip or solving a difficult puzzle.
"The immune system also dips into the same pot, which is big, but finite," says Baumeister, "and, we are pretty sure, so does women's premenstrual syndrome. Having a cold tends to reduce your self-control, and PMS does the same. We get cranky and irritable, but it's not that we have nastier impulses – it's that our usual restraints have become weakened."
So best avoid trying to do too many things involving mental effort at the same time, or if you're ill. As with a muscle, though, you can train your willpower. Even small, day-to-day acts of willpower such as maintaining good posture, speaking in complete sentences or using a computer mouse with the other hand, can pay off by reinforcing longer-term self-control in completely unrelated activities, Baumeister has found. People previously told to sit or stand up straight whenever they remembered later performed much better in lab willpower tests.
The final way in which willpower resembles a mental "muscle" is that when its strength is depleted, it can be revived with glucose. Getting a decent night's sleep and eating well – good, slow-burning fuel – is important in the exercise of willpower, but in times of dire need a quick shot of sugar can, according to Baumeister's lab tests, make all the difference.
