Quotes of the Day

When it comes to good-time holidays, Lent does not rank very high. Nor do Ramadan or Yom Kippur, of course, and no wonder. They are all about saying no to something (or many things) you love. Where's the egg nog and holiday joy in all that? But we observe these less-than-festive celebrations all the same — and we have good reason to do so. There are hidden benefits to so much ritualized self-denial.

One of the open secrets of all religions is that even if you don't care for the priestly raiment in which their traditions come draped, some of them can be very healthy all the same. And those, like Lent, whose secular message is nothing more complicated than practicing self-control, can be among the most salutary of all — something science is beginning to prove.

Willpower is a quality that can be in short supply in all of us but it's one that, as we report in this week's TIME, is increasingly seen as cultivatable. Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used. What's more, neurologists and behavioral psychologists generally think of willpower as what's known as "domain general," which means that the more you practice it to control one behavior — say, overeating — the more it starts to apply itself to other parts of your life like exercising more or drinking less.

Roy Baumeister, a psychologist at Florida State University and author of the straightforwardly titled book Willpower, has conducted experiments in which subjects were given uncomfortable tasks to perform in a lab, such as holding their hand in ice water or squeezing an exercise grip. They were then sent home and given a random rule to observe for two weeks — not swearing, say, or using the non-dominant hand for certain things like opening doors. After that period was over, they returned to the lab. Those subjects who had been assigned a rule and had followed it did better on their ice water or hand grip tasks when they tried them again than a control group that had been given no such homework. The two weeks of practicing resolve seemed to have generalized itself to other situations.

"An Australian group did something similar," says Baumeister. "They had people work on a problem in their lives — like managing money — for two weeks. Then they came back and had to focus on a computer task that involved catching three moving triangles while a distracting comedy video played. Doing the work at home seemed to improve their motivation in the lab."

The precise mechanism at work here is not clear. Changes in behavior are often reflected in — or enabled by — changes in the brain, but studies with functional magnetic resonance imaging (fMRI) have not yet shown any physical differences in the brains of people who practice lab-assigned discipline tasks. Still, other kinds of focus and training do change the brain.

"Both exercise and meditation lead to greater neuron density in the prefrontal cortex," says Kelly McGonigal, a psychologist at Stanford University and author of the new book The Willpower Instinct. It's in that region that executive skills such as impulse control and judgment live — making it a very good place to be adding neuronal connections. Even if the short-term exercises Baumeister assigns don't have the same demonstrable effect, McGonigal has little doubt that they still "train up the skill set involved in self-awareness and practicing habits consistent with your goals."

That sense of conscious adherence and regular practice is precisely the reason religious observances that prescribe strict rituals of self-denial can be so powerful. Every time an observer of Lent craves — and resists the lure of — a forbidden indulgence is a tiny reminder of a commitment made. The same is true for Muslims who tolerate their Ramadan hunger until the sun goes down. And while the 24 hours of Yom Kippur do not provide the same weeks-long training the other holidays do, the rules are stricter — with no food, no water, no bathing or washing, from sundown to sundown. Most of the day is spent in synagogue as well, which can be a trial of its own for people growing woozy with hunger.

The expressed liturgical purpose of all of these holidays is to teach piety, humility and submission and to atone for wrongs. But present-day spiritual leaders also speak of just the kind of willpower calisthenics the scientists do, though they call it "transfer training." Prohibitions against shellfish and pork in Jewish homes may have begun long ago with health concerns over the cleanliness of both foods, but modern inspections have effectively eliminated that worry. Still when you can pass up bacon no matter how good it smells or say no to a just-boiled lobster with a cup of drawn butter, that same facility with discipline can be applied to other areas of your life.

Distilling religious ritual down to scientific principle can be tricky — not just because it diminishes the more transcendent experiences of believers but because it can seem to justify a sort of cynical dismissiveness in non-believers. But — culture-war absolutism not withstanding — both truths can exist simultaneously. A vigorous workout at your gym may make you feel great — but so can a joyous round of gospel singing, clapping and foot-stomping. Are rising endorphins and lower cortisol levels involved in both? Probably. But is that all that's going on? Not to the believers it isn't.

The best thing about science is that hard, empirical answers are always there if you look hard enough. The best thing about religion is that the very absence of that certainty is what requires — and gives rise to — deep feelings of faith. Lent — and Ramadan and Yom Kippur — teach both.

Kluger is a senior editor at TIME and the author The Sibling Effect. The views expressed are solely his own.

• Jeffrey Kluger