When a habit emerges, the brain stops fully participating in decision making. It stops working so hard, or diverts focus to other tasks. Unless you deliberately fight a habit, unless you find new routines, the pattern will unfold automatically. However, simply understanding how habits work, learning to recognize the cues and rewards that drive them, makes them surprisingly easier to control. Once you break a habit into its components, you can fiddle with the gears.
Charles Duhigg’s “The Power of Habit” explores the science behind why habits exist, how they work, and most importantly, how they can be changed. Drawing on hundreds of academic studies, interviews with scientists and executives, and research conducted at dozens of companies, Duhigg presents a compelling framework for understanding the habits that shape our lives, organizations, and societies.
At the core of Duhigg’s exploration is the discovery of a simple neurological loop that underlies every habit. This loop consists of three parts: a cue, a routine, and a reward. The basal ganglia—a small, primitive region of the brain—stores habits even when the rest of the brain goes to sleep.
The discovery of this loop came from studying patients like Eugene Pauly, who lost his memory but could still form new habits. Despite being unable to remember new information for more than a few seconds, Eugene could find his way home from walks, find the kitchen, and even learn to choose the correct object in experiments. His basal ganglia had escaped damage, allowing habits to function independently of conscious memory.
This process—where the brain converts a sequence of actions into an automatic routine—is known as “chunking.” It explains why backing out of a driveway becomes automatic or why we brush our teeth without thinking. The brain is constantly looking for ways to save effort, turning repeated behaviors into habits so our minds can focus on other tasks.
The Three-Step Loop:
Cue: A trigger that tells the brain to go into automatic mode and which habit to use
Routine: The behavior itself—physical, mental, or emotional
Reward: The payoff that helps the brain determine if this loop is worth remembering
Over time, the cue and reward become intertwined, creating a powerful sense of anticipation and craving. This craving is what makes habits so powerful—the brain begins to expect the reward before it arrives.
Claude Hopkins, the advertising pioneer who turned Pepsodent into a worldwide phenomenon, demonstrated how new habits can be created. His genius was finding a simple cue—tooth film—and a clear reward—beautiful teeth. But the real secret to Pepsodent’s success was something Hopkins didn’t even realize: the toothpaste created a craving through its tingling sensation.
This craving is the engine of the habit loop. Studies with monkeys showed that once a habit is formed, the brain anticipates the reward. When the reward doesn’t arrive, a craving emerges. This craving drives the behavior even in the face of distractions.
The formula for creating new habits:
Find a simple and obvious cue
Clearly define the reward
Cultivate a craving for that reward
Procter & Gamble’s experience with Febreze illustrates this perfectly. Initially, Febreze failed because the cue—bad smells—wasn’t noticed by the people who needed it most. Customers became desensitized to odors. The breakthrough came when Febreze was repositioned as a reward at the end of a cleaning routine, not as a solution to a problem. The product created a craving: the desire for a fresh scent after cleaning. Within a year, sales exploded.
You can never truly extinguish a bad habit. Instead, to change a habit, you must keep the old cue, deliver the old reward, but insert a new routine. This is the Golden Rule of habit change.
Tony Dungy applied this principle to transform the Tampa Bay Buccaneers. Rather than creating new habits, Dungy changed players’ old ones by keeping the same cues and rewards but shifting the routines. Players learned to react automatically to visual cues on the field without thinking, which made them faster and more effective.
Alcoholics Anonymous applies the same principle. AA helps alcoholics identify the cues that trigger their drinking and the rewards they seek from alcohol (escape, relaxation, companionship, relief from anxiety). Then it provides new routines—meetings, sponsorship, prayer—that deliver the same rewards. But AA also adds an essential ingredient: belief. Participants must believe change is possible, and this belief often emerges through the support of a group.
The habit reversal training used to stop nail biting follows the same pattern. Patients identify the cue (tension in the fingers), recognize the reward (physical stimulation), and then insert a competing response—a new routine that provides similar physical stimulation without the destructive behavior.
Some habits matter more than others. Keystone habits start a chain reaction that transforms everything else. When Paul O’Neill became CEO of Alcoa, he didn’t focus on profits or efficiency. He focused on worker safety—a keystone habit that would ripple through the entire organization.
O’Neill’s approach was brilliant in its simplicity: Any time an employee was injured, the unit president had to report it to O’Neill within twenty-four hours and present a plan for preventing future injuries. To achieve this, new communication systems were built, workers were empowered to report problems, and the entire hierarchy became more responsive.
The results were extraordinary. As safety improved, costs dropped and quality rose. Workers started suggesting improvements in other areas. Alcoa became both the safest aluminum company and one of the most profitable, with its market capitalization increasing by $27 billion during O’Neill’s tenure.
Keystone habits work through:
Small wins: Initial successes that build momentum
Creating structures that help other habits flourish
Establishing cultures where new values become ingrained
Exercise is a keystone habit for many people. When people start exercising, they often begin eating better, working more productively, smoking less, and showing more patience. Family meals and making the bed are other examples—these small habits create conditions for other positive behaviors to emerge.
Willpower is the single most important keystone habit for individual success. Research shows that self-discipline predicts academic performance more robustly than IQ.
Willpower works like a muscle—it can be exhausted through use, but it can also be strengthened through exercise. Studies with radishes and cookies demonstrated that exerting willpower on one task depletes it for subsequent tasks. However, studies also show that strengthening willpower in one area spills over to other areas of life.
Starbucks has built its employee training around this principle. The company teaches employees specific routines for dealing with stressful situations—like the LATTE method for handling angry customers. By practicing these routines, employees develop willpower habits that become automatic. Employees also need a sense of control; when people feel they have autonomy, their willpower goes further.
The key to building willpower is anticipating inflection points—moments when you’re most likely to give in—and pre-planning a response. Scottish patients recovering from hip surgery who wrote detailed plans for their recovery exercised almost twice as fast as those who didn’t.
Organizations rely on institutional habits—routines and truces that allow work to get done. These habits create balance between warring factions and provide unwritten rules that let employees navigate their environment.
But sometimes these truces become destructive. At Rhode Island Hospital, nurses and doctors had established a dysfunctional peace where nurses absorbed abuse rather than speaking up. This led to catastrophic mistakes, including a surgeon operating on the wrong side of a patient’s head.
The London Underground fire at King’s Cross in 1987 demonstrated how institutional habits can kill. Employees followed their prescribed roles so rigidly that warning signs of fire were ignored. No one had ultimate responsibility for passenger safety because the truces between departments prevented anyone from stepping outside their designated role.
Crises create opportunities for change. Leaders can use moments of turmoil to remake organizational habits. After the King’s Cross fire, the entire system was overhauled. Similarly, Rhode Island Hospital used its crisis to implement new safety procedures, empower nurses, and create a culture of teamwork. Today, it’s a leading institution for patient safety.
Target’s data analytics department, led by statistician Andrew Pole, demonstrates how companies use habits to predict and manipulate consumer behavior. Target can identify pregnant women based on their purchasing patterns, sometimes before they’ve told anyone. By analyzing products like unscented lotion, supplements, and washcloths, the company can determine a woman’s due date.
The challenge is marketing to these women without revealing that Target knows their secret. The solution is to “sandwich” diaper coupons between unrelated products, so the advertising seems random rather than creepily prescient. This mirrors how radio stations made “Hey Ya!” a hit by playing it between familiar songs—making the unfamiliar seem familiar.
Social habits explain how movements spread. The Montgomery bus boycott began because Rosa Parks was embedded in a dense network of friendships. Her arrest triggered the social habits of friendship—people rallied to support someone they knew personally.
But the protest grew because of weak ties—the connections between acquaintances. Peer pressure and community expectations compelled participation. If everyone else was boycotting, it would be embarrassing to ride the bus.
For a movement to endure, participants must develop new habits that change their sense of identity. Martin Luther King Jr. gave protesters a new lens: nonviolence and love. This wasn’t just a tactic; it was a new way of being that transformed how participants saw themselves.
Rick Warren applied the same principles to build Saddleback Church. People were attracted by the community’s weak ties (the congregation), then pushed into small groups of close friends, and finally given new spiritual habits that sustained their faith.
The question of whether we’re responsible for our habits is complex. Cases like Brian Thomas, who killed his wife during a sleep terror, show that habits can overwhelm conscious control. Thomas had no awareness or choice; he was following a primal habit.
Angie Bachmann’s gambling addiction presents a different case. Her brain scans show that pathological gamblers process near-misses as wins—a neurological difference. Yet she was held responsible for her losses.
The distinction lies in awareness. Thomas had no knowledge of his sleep terror habits. Bachmann knew she had a gambling problem and had the capacity to change. Once you know a habit exists, you have the responsibility to change it.
William James, the pioneering psychologist, provides a framework for understanding this: “My first act of free will shall be to believe in free will.” We must choose to believe that change is possible, and then make that belief a habit.
The appendix provides a practical framework for changing habits:
Step One: Identify the Routine
The routine is the behavior you want to change—the most obvious part of the loop.
Step Two: Experiment with Rewards
Try different rewards to identify what craving is driving the habit. After each experiment, write down the first three things that come to mind, then set an alarm for fifteen minutes. If you still feel the urge, you haven’t found the right reward yet.
Step Three: Isolate the Cue
Most cues fall into one of five categories:
Location
Time
Emotional state
Other people
Immediately preceding action
When the urge hits, write down these five things. Patterns will emerge.
Step Four: Have a Plan
Once you’ve identified the loop, make a plan that keeps the same cue and reward but inserts a new routine. Implementation intentions—specific plans for when and how you’ll execute the new routine—dramatically increase success rates.
Habits never disappear: They’re encoded in the brain’s structures, waiting for the right cues and rewards.
Habits can be changed: By keeping the cue and reward but shifting the routine.
Cravings drive habits: Understanding what you really crave makes change easier.
Willpower is a muscle: It can be exhausted but also strengthened through practice.
Keystone habits matter most: Focusing on a few critical habits can transform everything else.
Belief is essential: Change is more likely when you believe it’s possible—and belief grows through community.
Crises create opportunity: Disruption can be a chance to remake habits.
Social habits shape movements: Change spreads through strong ties, weak ties, and new identities.
Awareness brings responsibility: Once you understand a habit, you have the power and obligation to change it.
The power of habit lies in the insight that our habits are what we choose them to be. Once we understand how habits work—the cue, routine, reward loop, the craving that drives it, the golden rule of change, and the role of keystone habits and belief—we gain the ability to remake them.
As William James observed, “All our life, so far as it has definite form, is but a mass of habits.” These habits, once invisible, can become visible again through understanding. We can choose who we want to be and then grow “to the way in which they have been exercised, just as a sheet of paper or a coat, once creased or folded, tends to fall forever afterward into the same identical folds.”
The water, as David Foster Wallace noted, is habits—the unthinking choices and invisible decisions that surround us every day. By looking at them, they become visible again. And once visible, they can be changed.
