Those of us who struggle to resist junk foods or otherwise suffer a lack of will power will be heartened by some good and bad news from neuroscience.
First, the bad news. A slew of studies suggest that we each have a fixed neural reservoir of will power, and that if we use it on one thing, we have less for others. Tasks that demand some self-control make it harder for us to do the next thing that takes will power. In a typical experiment on this effect, people who first had to circle every ‘e’ in a long passage gave up sooner when they then had to watch a video of a fixed, boring, scene. The same loss of persistence has been found when people resist tempting foods, suppress emotional reactions, even make the effort to try to impress someone.
This all suggests we have a fixed will power budget, one we should be careful in spending. Some neuroscientists suspect that self-control consumes blood sugar, which takes a while to build up again, and so the depletion effect.
But the good news is that we can grow our will power; like a muscle, over time the more we use it, the more it gradually increases. But doing this takes, of all things, will power.
As the muscle of will grows, the larger our reservoir of self-discipline becomes. So people who are able to stick to a diet or exercise program for a few months, or who complete money-management classes, also reduce their impulse buying, how much junk food they eat and alcohol they drink. They watch less TV and do more housework. And this ability to delay grasping at gratification, much data shows, predicts greater career success.
This round-up of thinking on will power comes courtesy of Sandra Aamodt and Sam Wang, whose new book Welcome to Your Brain details the evidence about will power. But, writing in the New York Times, the duo pose a puzzle – while it’s clear that will power has limits, what brain mechanisms let us build it up?
That question brought to mind the conversation I had with Richard Davidson, an old friend and a brilliant neuroscientist at the University of Wisconsin (the conversation is available from www.morethansound.net). Davidson’s research these days focuses on neuroplasticity: how our experience shapes the brain throughout life. One surprise: though most of us learned that we have a fixed number of brain cells when we are born, and that we lose them steadily until we die, brain science now tells us the brain makes about 10,000 new cells every day, and that they migrate to where they are needed. Once there, each cell makes around 10,000 connections to other brain cells over the successive four months.
One site that helps us build will power, Davidson’s research finds, is located in the left prefrontal cortex, the brain’s executive center located just behind the forehead. Our plans and goals hatch here, and impulses are executed via this zone. One neural circuit inhibits emotional impulse, and can be strengthened by a range of methods. As Davidson explained to me in our conversation, one kind of training that seems to do this is mindfulness training, a secular form of meditation widely used in settings from businesses to outpatient clinics.
There are ways, it seems, to make it easier to “just say no” when we need to