A new book explains why we do what we routinely do and how corporations, NFL teams, and even you can learn to manipulate that behavior.

by Mark Healy

Journalist Charles Duhigg spent the past eight years exploring the secrets of unconscious behavior. His book, The Power of Habit, is an exploration of the habit loop — the dopamine-fueled cue-and-reward system we rely on to perform series of actions without much thought. It’s what allows us to brush our teeth while we’re planning dinner, or back the car out of the driveway while focused on that morning’s meeting. Duhigg, a New York Times reporter who co-authored a much-talked-about series of stories on Apple’s global labor practices, explains the neurological workings behind our habits. But he also explores how institutions, from Target to the Indianapolis Colts, have learned to manipulate routines to get an extra edge. Duhigg says the key to changing habits is to stop fighting them. “We all have habits. The key is to shift habits to the ­behaviors that I want.”

Why did humans develop a system of habits?
In terms of evolution, the big question for mammals was, “How can I think better with a smaller brain?” — because mammals succeed when they stand upright, but to do that you have to have a relatively small head. So our body was trying to figure out how to have a small brain and still think really hard. The answer was a neurological system that allows us to do certain behaviors without thinking. And the only way to encode those behaviors is to use a reward that we begin anticipating when we see the cue.

So how do you make this habit loop work for you?
Most people think of habit as a routine, but it’s actually a cue, a routine, and a reward. Let’s say you want to create an exercise habit, like running. You need a cue to remind you to go running. Study after study has shown that the best way to do this is to choose a cue — a certain pattern of behavior, like putting your running shoes next to your bed each night — and then to give yourself a reward. So as soon as you get home from running, eat a piece of chocolate. The cue and the reward become interrelated, so when you see that cue, your brain begins expecting the reward. In fact, it’s going to start enjoying that reward even before it’s delivered, and that’s what will push you into the behavior. In two weeks you won’t need chocolate. Your brain will come to enjoy the running itself — the endorphin rush, the sense of accomplishment — but you have to bootstrap your brain into developing the habit loop.

You mean that the brain learns to ­anticipate the reward?
Exactly. We know from looking at [brain scans] of people and studies of animals that when you see the cue — the running shoes by your bed, for example — your brain will start releasing the dopamine, so getting out the door to jog doesn’t feel hard at all.

But do some habits tend to affect us more than others?
Yes. For some reason, when you change one habit in someone’s life, it makes other habits more pliable, more flexible to change. Research on this has shown that when people start habitually exercising, other changes happen: They start eating healthier, which kind of makes sense, but they also start using their credit cards less. They tend to do their dishes earlier in the evening; they procrastinate less. They get to work earlier. The keystone habit seems to unlock all these other changes.

Is it because we’re getting dopamine through exercise that we don’t need the rush that comes from buying something new?
That’s one hypothesis. The other reason is that while there are simple rewards like “I eat chocolate,” the real rewards that drive behavior are more sophisticated. One of the things that happens when you start running is you begin proving to yourself that you’re the type of person who habitually runs, so your brain goes from expecting the simple reward to anticipating the sophisticated reward. Rather than craving chocolate, you begin craving a sense of accomplishment.

And that explains why people who are friendly with other people at the gym are also more likely to go to the gym.
That’s exactly right. And I think, again, it’s these rewards working on two levels: The first, the simple reward is, I see that guy I like, and he sees me, and we chat for five minutes. It’s just fun to see someone whom you have something in common with. But then you’re also kicking in this second-level reward, the pride of self, because you see it reflected in other people. All of those guys know that I’m showing up to the gym every day, so I guess I’m the type of guy that shows up every day, which is pretty badass. And that’s when the habit just becomes so strong.