The Power of Habit: Why We Do What We Do and How to Change

by Charles Duhigg

Habits aren’t destiny. As the next two chapters explain, habits can be ignored, changed, or replaced. But the reason the discovery of the habit loop is so important is that it reveals a basic truth: When a habit emerges, the brain stops fully participating in decision making. It stops working so hard, or diverts focus to other tasks. So unless you deliberately fight a habit—unless you find new routines—the pattern will unfold automatically. However, simply understanding how habits work—learning the structure of the habit loop—makes them easier to control. Once you break a habit into its components, you can fiddle with the gears. “We’ve done experiments where we trained rats to run down a maze until it was a habit, and then we extinguished the habit by changing the placement of the reward,” Ann Graybiel, a scientist at MIT who oversaw many of the basal ganglia experiments, told me. “Then one day, we’ll put the reward in the old place, and put in the rat, and, by golly, the old habit will reemerge right away. Habits never really disappear. They’re encoded into the structures of our brain, and that’s a huge advantage for us, because it would be awful if we had to relearn how to drive after every vacation. The problem is that your brain can’t tell the difference between bad and good habits, and so if you have a bad one, it’s always lurking there, waiting for the right cues and rewards.”20

Habits aren’t destiny. As the next two chapters explain, habits can be ignored, changed, or replaced. But the reason the discovery of the habit loop is so important is that it reveals a basic truth: When a habit emerges, the brain stops fully participating in decision making. It stops working so hard, or diverts focus to other tasks. So unless you deliberately fight a habit—unless you find new routines—the pattern will unfold automatically. However, simply understanding how habits work—learning the structure of the habit loop—makes them easier to control. Once you break a habit into its components, you can fiddle with the gears. “We’ve done experiments where we trained rats to run down a maze until it was a habit, and then we extinguished the habit by changing the placement of the reward,” Ann Graybiel, a scientist at MIT who oversaw many of the basal ganglia experiments, told me. “Then one day, we’ll put the reward in the old place, and put in the rat, and, by golly, the old habit will reemerge right away. Habits never really disappear. They’re encoded into the structures of our brain, and that’s a huge advantage for us, because it would be awful if we had to relearn how to drive after every vacation. The problem is that your brain can’t tell the difference between bad and good habits, and so if you have a bad one, it’s always lurking there, waiting for the right cues and rewards.”20

First, find a simple and obvious cue. Second, clearly define the rewards.

Studies have documented that families who habitually eat dinner together seem to raise children with better homework skills, higher grades, greater emotional control, and more confidence.11 Making your bed every morning is correlated with better productivity, a greater sense of well-being, and stronger skills at sticking with a budget.12 It’s not that a family meal or a tidy bed causes better grades or less frivolous spending. But somehow those initial shifts start chain reactions that help other good habits take hold.

Small wins are exactly what they sound like, and are part of how keystone habits create widespread changes. A huge body of research has shown that small wins have enormous power, an influence disproportionate to the accomplishments of the victories themselves. “Small wins are a steady application of a small advantage,” one Cornell professor wrote in 1984. “Once a small win has been accomplished, forces are set in motion that favor another small win.”14 Small wins fuel transformative changes by leveraging tiny advantages into patterns that convince people that bigger achievements are within reach.15

at Stanford had tested the willpower of a group of four-year-olds. The kids were brought into a room and presented with a selection of treats, including marshmallows. They were offered a deal: They could eat one marshmallow right away, or, if they waited a few minutes, they could have two marshmallows. Then the researcher left the room. Some kids gave in to temptation and ate the marshmallow as soon as the adult left. About 30 percent managed to ignore their urges, and doubled their treats when the researcher came back fifteen minutes later. Scientists, who were watching everything from behind a two-way mirror, kept careful track of which kids had enough self-control to earn the second marshmallow. Years later, they tracked down many of the study’s participants. By now, they were in high school. The researchers asked about their grades and SAT scores, ability to maintain friendships, and their capacity to “cope with important problems.” They discovered that the four-year-olds who could delay gratification the longest ended up with the best grades and with SAT scores 210 points higher, on average, than everyone else. They were more popular and did fewer drugs. If you knew how to avoid the temptation of a marshmallow as a preschooler, it seemed, you also knew how to get yourself to class on time and finish your homework once you got older, as well as how to make friends and resist peer pressure. It was as if the marshmallow-ignoring kids had self-regulatory skills that gave ...

Willpower isn’t just a skill. It’s a muscle, like the muscles in your arms or legs, and it gets tired as it works harder, so there’s less power left over for other things.”

Oaten and Cheng did one more experiment. They enrolled forty-five students in an academic improvement program that focused on creating study habits.11 Predictably, participants’ learning skills improved. And the students also smoked less, drank less, watched less television, exercised more, and ate healthier, even though all those things were never mentioned in the academic program. Again, as their willpower muscles strengthened, good habits seemed to spill over into other parts of their lives.

“When you learn to force yourself to go to the gym or start your homework or eat a salad instead of a hamburger, part of what’s happening is that you’re changing how you think,” said Todd Heatherton, a researcher at Dartmouth who has worked on willpower studies.12 “People get better at regulating their impulses. They learn how to distract themselves from temptations. And once you’ve gotten into that willpower groove, your brain is practiced at helping you focus on a goal.”

“That’s why signing kids up for piano lessons or sports is so important. It has nothing to do with creating a good musician or a five-year-old soccer star,” said Heatherton. “When you learn to force yourself to practice for an hour or run fifteen laps, you start building self-regulatory strength. A five-year-old who can follow the ball for ten minutes becomes a sixth grader who can start his homework on time.”14

The solution, Starbucks discovered, was turning self-discipline into an organizational habit.

As the psychologist scrutinized the booklets, she saw that many of the plans had something in common: They focused on how patients would handle a specific moment of anticipated pain. The man who exercised on the way to the bathroom, for instance, knew that each time he stood up from the couch, the ache was excruciating. So he wrote out a plan for dealing with it: Automatically take the first step, right away, so he wouldn’t be tempted to sit down again. The patient who met his wife at the bus stop dreaded the afternoons, because that stroll was the longest and most painful each day. So he detailed every obstacle he might confront, and came up with a solution ahead of time.

“One of the systems we use is called the LATTE method. We Listen to the customer, Acknowledge their complaint, Take action by solving the problem, Thank them, and then Explain why the problem occurred.20

This is how willpower becomes a habit: by choosing a certain behavior ahead of time, and then following that routine when an inflection point arrives.

Routines reduce uncertainty

Take, for instance, how you buy food. Chances are, the first things you see upon entering your grocery store are fruits and vegetables arranged in attractive, bountiful piles. If you think about it, positioning produce at the front of a store doesn’t make much sense, because fruits and vegetables bruise easily at the bottom of a shopping cart; logically, they should be situated by the registers, so they come at the end of a trip. But as marketers and psychologists figured out long ago, if we start our shopping sprees by loading up on healthy stuff, we’re much more likely to buy Doritos, Oreos, and frozen pizza when we encounter them later on. The burst of subconscious virtuousness that comes from first buying butternut squash makes it easier to put a pint of ice cream in the cart later.

Or take the way most of us turn to the right after entering a store. (Did you know you turn right? It’s almost certain you do. There are thousands of hours of videotapes showing shoppers turning right once they clear the front doors.) As a result of this tendency, retailers fill the right side of the store with the most profitable products they’re hoping you’ll buy right off the bat. Or consider cereal and soups: When they’re shelved out of alphabetical order and seemingly at random, our instinct is to linger a bit longer and look at a wider selection. So you’ll rarely find Raisin Bran next to Rice Chex. Instead, you’ll have to search the shelves for the cereal you want, and maybe get tempted to grab an extra box of another brand.1

Just as the scientists at MIT discovered that behavioral habits prevent us from becoming overwhelmed by the endless decisions we would otherwise have to make each day, listening habits exist because, without them, it would be impossible to determine if we should concentrate on our child’s voice, the coach’s whistle, or the noise from a busy street during a Saturday soccer game. Listening habits allow us to unconsciously separate important noises from those that can be ignored.

Whether selling a new song, a new food, or a new crib, the lesson is the same: If you dress a new something in old habits, it’s easier for the public to accept it.

Rosa Parks wasn’t the first Black passenger jailed for breaking Montgomery’s bus segregation laws. She wasn’t even the first that year. In 1946, Geneva Johnson had been arrested for arguing with a Montgomery bus driver over seating.5 In 1949, Viola White, Katie Wingfield, and two Black children were arrested for sitting in the white section and refusing to move.6 That same year, two Black teenagers visiting from New Jersey—where buses were integrated—were arrested and jailed after breaking the law by sitting next to a white man and a boy.7 In 1952, a Montgomery policeman shot and killed a Black man when he argued with a bus driver. In 1955, just months before Parks was taken to jail, Claudette Colvin and Mary Louise Smith were arrested in separate incidents for refusing to give their seats to white passengers.

If you believe you can change—if you make it a habit—the change becomes real. This is the real power of habit: the insight that your habits are what you choose them to be. Once that choice occurs—and becomes automatic—it’s not only real, it starts to seem inevitable, the thing, as James wrote, that bears “us irresistibly toward our destiny, whatever the latter may be.”

Since The Power of Habit was published, there’s been an explosion of research looking at mental habits and, in particular, habitual behaviors like gratitude.2 In one study published in 2016, for instance, researchers at Indiana University scrutinized 293 people who had come to the University’s mental health offices looking for counseling.3 All of the participants received therapy and, in addition, the researchers instructed a third of them “to write one letter of gratitude to another person each week, for three weeks.” Another group was instructed to write introspectively about their deepest thoughts and experiences. A third group was not assigned any writing tasks. Twelve weeks later, when the researchers polled all the participants, they found the grateful letter writers “reported significantly better mental health” and, on tests of well-being, indicated they had improved at as much as twice the pace of the other groups. This was particularly interesting because, in most cases, the letter writers had never sent their letters. They had simply scribbled their gratefulness and then set the cards aside.

Why had this gratitude habit proved so powerful? The researchers began examining the letters and discovered they tended to “use a greater proportion of ‘we’ words and positive emotion words, and a lower percentage of negative emotion words,” when compared to the writings of the introspective group. What’s more, when the researchers looked at the neurological activity of the grateful letter writers, they found “greater neural sensitivity in the medial prefrontal cortex, a brain area associated with learning and decision making.” In other words, developing a habit of writing grateful notes had put the letter writers into positive mindsets, had reminded them of how many friends and supporters surrounded them, had activated those parts of their brains that made it easier to make decisions and act. The letter writing habit had generated other mental habits that had made it easier to do things like put the dishes in the dishwasher, or forgive an incompetent barista.

THE FRAMEWORK: Identify the routine Experiment with rewards Isolate the cue Have a plan

In the prologue, we learned that a habit is a choice that we deliberately make at some point, and then stop thinking about, but continue doing, often every day.