Atomic Habits Chapter 15

The Cardinal Rule of Behavior Change

In the late 1990s, a public health worker named Stephen Luby left his hometown of Omaha, Nebraska, and bought a one-way ticket to Karachi, Pakistan.

Karachi was one of the most populous cities in the world. By 1998 over nine million people it home. It was the economic center of Pakistan and a transportation hub, featuring some of the most active airports and seaports in the region. In the commercial parts of town, you could find standard urban amenities amidst bustling downtown streets. However, Karachi was also one of the least livable cities in the world.

Over 60 percent of Karachi’s residents lived in squatter settlements and slums. These densely packed neighborhoods were filled with makeshift houses cobbled together from old boards, cinder blocks, and other discarded materials. There was no waste removal system, no electricity grid, and no clean water supply. When dry, the streets were a mix of dust and trash; when wet, they became muddy pits of sewage. Mosquito colonies thrived in pools of stagnant water, and children played among the garbage.

The unsanitary conditions led to widespread illness and disease. Contaminated water sources caused epidemics of diarrhea, vomiting, and abdominal pain. Nearly one-third of the children living there were malnourished. With so many people crammed into such a small space, viruses and bacterial infections spread rapidly. It was this public health crisis that had brought Stephen Luby to Pakistan.

Luby and his team realized that in an environment with poor sanitation, the simple habit of washing hands could make a significant difference in the residents' health. However, they soon discovered that many people were already aware of the importance of handwashing. Yet, despite this knowledge, many residents washed their hands in a haphazard fashion. Some individuals would quickly run their hands under water; others would wash only one hand. Many would simply forget to wash their hands before preparing food. Everyone acknowledged that handwashing was important, but few made it a habit. The issue wasn’t knowledge—it was consistency.

That’s when Luby and his team partnered with Procter & Gamble to supply the neighborhood with Safeguard soap. Compared to standard bars of soap, using Safeguard was a more enjoyable experience. “In Pakistan, Safeguard was a premium soap,” Luby recalled. “The study participants commonly mentioned how much they liked it.” The soap lathered easily and smelled great, making handwashing slightly more pleasurable.

“I see the goal of handwashing promotion not as behavior change but as habit adoption,” Luby said. “It is much easier for people to adopt a product that provides a strong positive sensory signal, such as the mint taste of toothpaste, than to adopt a habit that does not provide pleasurable sensory feedback, like flossing one's teeth. The marketing team at Procter & Gamble aimed to create a positive handwashing experience.”

Within months, the researchers observed a rapid improvement in the health of the children in the neighborhood. The rate of diarrhea fell by 52 percent; pneumonia rates decreased by 48 percent; and impetigo, a bacterial skin infection, diminished by 35 percent. 

The long-term effects were even more promising. “We returned to some of the households in Karachi six years later,” Luby told me. “Over 95 percent of households that had been given the soap for free and encouraged to wash their hands had a handwashing station with soap and water available during our visit. We hadn't provided any soap to the intervention group for over five years, but they had become so habituated to washing their hands that they maintained the practice.” This was a powerful example of the fourth and final Law of Behavior Change: make it satisfying.

We are more likely to repeat a behavior when the experience is satisfying. This is entirely logical. Feelings of pleasure—even minor ones like washing your hands with soap that smells nice and lathers well—signal to the brain: “This feels good. Do this again next time.” Pleasure teaches your brain that a behavior is worth remembering and repeating.

Take the story of chewing gum. Chewing gum was sold commercially throughout the 1800s, but it wasn’t until Wrigley launched in 1891 that it became a worldwide habit. Early versions were made from relatively bland resins—chewy, but not tasty. Wrigley revolutionized the industry by adding flavors like Spearmint and Juicy Fruit, making the product flavorful and fun to use. They went a step further and began promoting chewing gum as a pathway to a clean mouth, with advertisements urging readers to “Refresh Your Taste.” Tasty flavors and the feeling of a fresh mouth provided immediate reinforcement, making the product satisfying to use. Consumption skyrocketed, and Wrigley became the largest chewing gum company in the world.

Toothpaste followed a similar trajectory. Manufacturers achieved great success by adding flavors like spearmint, peppermint, and cinnamon to their products. These flavors don’t improve the effectiveness of toothpaste; they simply create a “clean mouth” sensation and make the experience of brushing teeth more pleasurable. My wife actually stopped using Sensodyne because she didn’t like the aftertaste and switched to a brand with a stronger mint flavor, which she found more satisfying.

Conversely, if an experience is not satisfying, we have little reason to repeat it. In my research, I encountered the story of a woman who had a narcissistic relative who drove her crazy. In an attempt to spend less time with this egomaniac, she acted as dull and boring as possible whenever he was around. Within a few encounters, he started avoiding her due to her uninteresting demeanor.

Stories like these illustrate the Cardinal Rule of Behavior Change: What is rewarded is repeated. What is punished is avoided. You learn what to do in the future based on what you were rewarded for doing (or punished for doing) in the past. Positive emotions cultivate habits, while negative emotions destroy them.

The first three laws of behavior change—make it obvious, make it attractive, and make it easy—increase the odds that a behavior will be performed this time. The fourth law of behavior change—make it satisfying—increases the odds that a behavior will be repeated next time, completing the habit loop.

However, there is a trick: we are not looking for just any type of satisfaction; we are seeking immediate satisfaction.

The Mismatch Between Immediate and Delayed Rewards

Imagine you’re an animal roaming the plains of Africa—a giraffe, an elephant, or a lion. On any given day, most of your decisions have immediate impacts. You are always focused on basic needs: what to eat, where to sleep, and how to avoid predators. You live in what scientists call an immediate-return environment, where actions deliver clear, immediate outcomes.

Now switch back to your human self. In modern society, many of the choices you make today will not benefit you immediately. If you perform well at work, you receive a paycheck in a few weeks. If you exercise today, you may not notice a difference until you’re healthier next year. If you save money now, you might have enough for retirement decades later. You live in what scientists refer to as a delayed-return environment, where actions often take years before delivering their intended benefits.

The human brain did not evolve for life in a delayed-return environment. The earliest remains of modern humans, known as *Homo sapiens sapiens*, are approximately two hundred thousand years old. These were the first humans to possess a brain similar to ours, particularly the neocortex—the newest part of the brain responsible for higher functions like language—which was roughly the same size two hundred thousand years ago as it is today. You are carrying around the same hardware as your Paleolithic ancestors.

Only recently—over the past five hundred years—has society shifted to a predominantly delayed-return environment. Compared to the age of the brain, modern society is brand new. In the last one hundred years alone, we’ve witnessed the rise of the automobile, the airplane, the television, the personal computer, the internet, the smartphone, and even pop culture icons like Beyoncé. While the world has transformed dramatically, human nature has changed little.

Similar to other animals on the African savannah, our ancestors spent their days responding to immediate threats, securing their next meal, and seeking shelter from storms. It made sense for them to place a high value on instant gratification, as the distant future was less of a concern. After thousands of generations in an immediate-return environment, our brains evolved to prefer quick payoffs over long-term ones.

Behavioral economists refer to this tendency as time inconsistency. In other words, the way your brain evaluates rewards is inconsistent over time. You tend to value the present more than the future. While this tendency typically serves us well, it occasionally leads to problems. 

Why would someone smoke even though they know it increases the risk of lung cancer? Why would someone overeat despite knowing the risks of obesity? Why would someone engage in unsafe sex despite the potential consequences of sexually transmitted diseases? Once you understand how the brain prioritizes rewards, the answers become clear: the consequences of bad habits are delayed, while the rewards are immediate. Smoking might kill you in ten years, but it reduces stress and satisfies nicotine cravings now. Overeating is harmful in the long run but feels great in the moment. Sex—safe or unsafe—provides immediate pleasure, while the repercussions of disease and infection often won’t manifest for days, weeks, or even years.

Every habit produces multiple outcomes over time. Unfortunately, these outcomes are often misaligned. With our bad habits, the immediate outcome usually feels good while the ultimate outcome feels bad. With good habits, the reverse is true: the immediate outcome is unenjoyable, but the ultimate outcome feels good. The French economist Frédéric Bastiat accurately described this dilemma: “It almost always happens that when the immediate consequence is favorable, the later consequences are disastrous, and vice versa. . . . Often, the sweeter the first fruit of a habit, the more bitter are its later fruits.”

Put differently, the costs of your good habits are experienced in the present, while the costs of your bad habits manifest in the future.

The brain’s tendency to prioritize the present moment means you can’t rely solely on good intentions. When you create a plan—to lose weight, write a book, or learn a language—you are essentially making plans for your future self. Visualizing your desired future makes it easy to appreciate the importance of taking actions with long-term benefits. We all aspire to improve our lives; however, when moments of decision arrive, instant gratification often prevails. You are no longer making choices for Future You, who dreams of being fitter, wealthier, or happier. Instead, you are choosing for Present You, who seeks comfort, indulgence, and entertainment. As a general rule, the more immediate pleasure you gain from an action, the more critically you should evaluate whether it aligns with your long-term goals.

With a clearer understanding of what leads our brains to repeat some behaviors and avoid others, let’s refine the Cardinal Rule of Behavior Change: What is immediately rewarded is repeated. What is immediately punished is avoided.

Our penchant for instant gratification reveals an essential truth about success: because of our inherent wiring, most people will spend their day chasing quick hits of satisfaction. The path less traveled is the one of delayed gratification. If you are willing to wait for the rewards, you will face less competition and often achieve larger payoffs. As the saying goes, the last mile is always the least crowded.

This is precisely what research has shown. Individuals who are better at delaying gratification tend to have higher SAT scores, lower levels of substance abuse, a reduced likelihood of obesity, better stress management, and superior social skills. We have all seen this play out in our own lives. If you resist the temptation to watch television and prioritize completing your homework, you are likely to learn more and achieve better grades. If you avoid buying desserts and chips at the grocery store, you often end up eating healthier at home. Ultimately, success in nearly every field requires you to overlook immediate rewards in favor of delayed ones.

Here lies the challenge: most people know that delaying gratification is the wise approach. They desire the benefits of good habits—such as being healthy, productive, and at peace. However, these outcomes often fade from view at crucial decision-making moments. Fortunately, it is possible to train yourself to delay gratification, but you must work with human nature rather than against it. The best strategy is to add a bit of immediate pleasure to the habits that yield long-term rewards and introduce a bit of immediate pain to those that do not.

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HOW TO TURN INSTANT GRATIFICATION TO YOUR ADVANTAGE

The key to making a habit stick is to feel successful—even in small ways. Success is a signal that your habit has paid off and that the effort was worth it.

In a perfect world, the reward for a good habit would be the habit itself. However, in the real world, good habits often feel worthwhile only after they have provided you with tangible benefits. At the outset, it’s all about sacrifice. You’ve gone to the gym a few times, but you don’t yet feel stronger, fitter, or faster—at least not noticeably. It’s only after months of consistent effort, as you shed a few pounds or notice definition in your arms, that exercising for its own sake becomes easier. Initially, you need a reason to stay on track, which is why immediate rewards are essential. They keep you motivated while the delayed rewards accumulate in the background.

What we’re really discussing here—when talking about immediate rewards—is the conclusion of a behavior. The ending of any experience is crucial because we tend to remember it more than other phases. You want the conclusion of your habit to be satisfying. The best approach is to utilize reinforcement, which refers to using an immediate reward to increase the likelihood of a behavior. Habit stacking, which we covered in Chapter 5, ties your habit to an immediate cue, making it obvious when to start. Reinforcement connects your habit to an immediate reward, making it satisfying when you complete it.

Immediate reinforcement can be particularly helpful when dealing with habits of avoidance, which are behaviors you want to stop. It can be challenging to stick with habits like “no frivolous purchases” or “no alcohol this month” because nothing happens when you skip happy hour drinks or refrain from buying that pair of shoes. It can feel unsatisfying to avoid temptation, as there isn’t much reward in simply resisting.

One solution is to turn the situation on its head. Make avoidance visible. Open a savings account and label it for something you want—perhaps “Leather Jacket.” Whenever you pass on a purchase, deposit the same amount of money into the account. Decided to skip your morning latte? Transfer $5. Passed on another month of Netflix? Move $10 over. It’s like creating a loyalty program for yourself; the immediate reward of watching your savings grow feels much better than the sensation of deprivation. You make it satisfying to do nothing.

One of my readers and his wife employed a similar strategy. They wanted to cut down on dining out and start cooking together more. They labeled their savings account “Trip to Europe.” Whenever they opted to skip going out to eat, they transferred $50 into the account. At the end of the year, they used the savings for their vacation.

It’s important to choose short-term rewards that reinforce your identity rather than conflict with it. While buying a new jacket may be fine if you’re trying to lose weight or read more books, it doesn’t work if your goal is budgeting and saving money. Instead, consider rewarding yourself with activities that align with your long-term goals, such as taking a bubble bath or going for a leisurely walk, which supports your aspiration for more freedom and financial independence. Similarly, if your reward for exercising is indulging in a bowl of ice cream, you’re reinforcing conflicting identities, which cancels out the benefits. Instead, perhaps your reward could be a massage, which is a luxury that also aligns with caring for your body. Here, the short-term reward complements your long-term vision of becoming a healthier person.

Eventually, as intrinsic rewards like a better mood, increased energy, and reduced stress kick in, you’ll find yourself less focused on chasing secondary rewards. The identity itself becomes the reinforcer; you do it because it’s who you are, and it feels good to be you. The more a habit integrates into your life, the less you need external encouragement to follow through. Incentives can initiate a habit, but identity sustains it.

That said, it takes time for evidence to accumulate and for a new identity to emerge. Immediate reinforcement helps maintain motivation in the short term while you wait for long-term rewards to arrive.

In summary, a habit needs to be enjoyable to endure. Simple forms of reinforcement—like soap that smells great, toothpaste with a refreshing mint flavor, or seeing $50 added to your savings account—can provide the immediate pleasure necessary to appreciate a habit. Change is easier when it is enjoyable.

Chapter Summary

The fourth Law of Behavior Change is to make it satisfying. 

- We are more likely to repeat a behavior when the experience is satisfying.

- The human brain evolved to prioritize immediate rewards over delayed ones.

- The Cardinal Rule of Behavior Change: What is immediately rewarded is repeated, and what is immediately punished is avoided.

- To make a habit stick, you need to feel immediately successful, even in small ways.

- The first three laws of behavior change—make it obvious, make it attractive, and make it easy—increase the odds that a behavior will be performed this time. The fourth law—make it satisfying—increases the likelihood that the behavior will be repeated next time.

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