Apologies for the light blogging: I’m enjoying a little vacation from my computer. But here is a recent little article about willpower in the WSJ:
Willpower, like a bicep, can only exert itself so long before it gives out; it’s an extremely limited mental resource.
Given its limitations, New Year’s resolutions are exactly the wrong way to change our behavior. It makes no sense to try to quit smoking and lose weight at the same time, or to clean the apartment and give up wine in the same month. Instead, we should respect the feebleness of self-control, and spread our resolutions out over the entire year. Human routines are stubborn things, which helps explain why 88% of all resolutions end in failure, according to a 2007 survey of over 3,000 people conducted by the British psychologist Richard Wiseman. Bad habits are hard to break–and they’re impossible to break if we try to break them all at once.
Some simple tricks can help. The first step is self-awareness: The only way to fix willpower flaws is to know about them. Only then can the right mental muscles get strengthened, making it easier to succeed at our annual ritual of self-improvement.
The brain area largely responsible for willpower, the prefrontal cortex, is located just behind the forehead. While this bit of tissue has greatly expanded during human evolution, it probably hasn’t expanded enough. That’s because the prefrontal cortex has many other things to worry about besides New Year’s resolutions. For instance, scientists have discovered that this chunk of cortex is also in charge of keeping us focused, handling short-term memory and solving abstract problems. Asking it to lose weight is often asking it to do one thing too many.
In one experiment, led by Baba Shiv at Stanford University, several dozen undergraduates were divided into two groups. One group was given a two-digit number to remember, while the second group was given a seven-digit number. Then they were told to walk down the hall, where they were presented with two different snack options: a slice of chocolate cake or a bowl of fruit salad.
Here’s where the results get weird. The students with seven digits to remember were nearly twice as likely to choose the cake as students given two digits. The reason, according to Prof. Shiv, is that those extra numbers took up valuable space in the brain–they were a “cognitive load”–making it that much harder to resist a decadent dessert. In other words, willpower is so weak, and the prefrontal cortex is so overtaxed, that all it takes is five extra bits of information before the brain starts to give in to temptation.
This helps explain why, after a long day at the office, we’re more likely to indulge in a pint of ice cream, or eat one too many slices of leftover pizza. (In fact, one study by researchers at the University of Michigan found that just walking down a crowded city street was enough to reduce measures of self-control, as all the stimuli stressed out the cortex.) A tired brain, preoccupied with its problems, is going to struggle to resist what it wants, even when what it wants isn’t what we need.
There’s something unsettling about this scientific model of willpower. Most of us assume that self-control is largely a character issue, and that we would follow through on our New Year’s resolutions if only we had a bit more discipline. But this research suggests that willpower itself is inherently limited, and that our January promises fail in large part because the brain wasn’t built for success.
Everybody knows that the bicep has practical limitations: If we ask the muscle to hold too much, it will give out and drop everything on the floor. And just as our muscles get tired after a tough workout, and require a rest to recuperate, so does the poor prefrontal cortex need some time off.
In a 2002 experiment, led by Mark Muraven at the University at Albany, a group of male subjects was asked to not think about a white elephant for five minutes while writing down their thoughts. That turns out to be a rather difficult mental challenge, akin to staying focused on a tedious project at work. (A control group was given a few simple arithmetic problems to solve.) Then, Mr. Muraven had the subjects take a beer taste test, although he warned them that their next task involved driving a car. Sure enough, people in the white elephant group drank significantly more beer than people in the control group, which suggests that they had a harder time not indulging in alcohol.
There’s much more, including some great work by Roy Baumeister, et. al. on glucose, willpower and the self-defeating nature of dieting.