In a research study about habit change, Lisa Allen was “the scientists’ favorite participant.” For almost two decades, she smoked, drank, was obese, amassed thousands of dollars in debt, and struggled to keep a job. But in just a few months, she totally changed. She stopped smoking and drinking, shed 60 pounds, started running marathons, got a stable job and paid off her debt, and even went to grad school and purchased a house. She then joined the scientists’ study, which focused on how people can successfully correct their own destructive habits in a short period of time.
Duhigg begins with Lisa Allen’s story in order to emphasize that habit change is possible and show how profoundly habits shape people’s lives. Allen’s bad habits totally dominated her life—they limited her personal, financial, and professional success. Her turnaround was remarkable because she corrected so many bad habits in such a short period of time. This shows that even the most destructive, deeply ingrained habits are ultimately within people’s control. In other words, Duhigg promises that people can change any habit if they have the right tools.
Lisa Allen told the scientists that she decided to quit smoking a few months after a sudden and devastating divorce. After the divorce, she went on vacation to Cairo, but on her first morning there, she woke up exhausted and disoriented in her pitch-black hotel room and accidentally lit a pen on fire, thinking it was a cigarette. She then kicked over and shattered a water jug. Feeling desperate and out of control, she decided that “she needed a goal in her life.” She decided that she would return to Egypt in a year and do a trek in the desert. Over the next six months, Allen worked to improve her life. She started jogging instead of smoking. She changed her diet and sleep schedule, then started saving money and planning for her future.
Lisa Allen resolved to change her habits after hitting rock bottom. While many people view their habits as outside their control, Allen managed to change when she realized that habits were one of the few things she actually could control. This shows how motivation is a crucial ingredient in habit change: people must want to change in order to actually do it. Unfortunately, motivation is also the only ingredient that people have to supply for themselves. While Duhigg can teach people evidence-based techniques to change their habits in this book, people have to decide for themselves if their habits are worth changing.
In the laboratory, brain scans clearly showed the change in Allen’s habits. The neurological patterns associated with her old habits were still there, but she had also created new patterns for her new habits, and these were much more active. Like everyone else in the scientists’ study, Allen started by changing a single “keystone habit.” (For her, it was smoking.) This taught her how to reprogram her other habits. Her brain scans showed that, when she was hungry, areas of her brain associated with food cravings still lit up. But after her habit change, areas responsible for self-discipline and inhibition also lit up. Allen’s brain scans helped scientists understand how decisions turn into habits over time.
Allen’s brain scans show how science has given people remarkable new tools for improving themselves. They show that that building new habits doesn’t require infinite willpower; rather, it just requires people to make the right decision enough times for their brain to start making that decision automatically. By doing this, Allen’s brain scans show, anyone can permanently change their habits by altering their brain. Crucially, Duhigg explains that the secret isn’t eliminating bad habits—it’s replacing them with newer, better ones.
Charles Duhigg (the author) asks the reader about their habits: what do they do first thing in the morning? What did they eat for lunch? What did they do when they got home from work? William James famously wrote that “all our life, so far as it has definite form, is but a mass of habits.” In other words, most of people’s choices aren’t well-reasoned decisions—they’re habits. Over time, people’s habits deeply shape how they live and who they become.
Duhigg asks these questions and quotes William James in order to emphasize two important but contradictory truths about habits. First, they’re easy to overlook because they’re automatic. Most people probably don’t give much thought to their daily routines—indeed, the purpose of routines is to save energy. Second, habits are also incredibly important because they form the foundation for people’s everyday lives. Thus, Duhigg suggests that people can greatly improve their lives by paying attention to habits and learning to improve them.
This book is about scientists and marketers’ research into how habits work and change. The first section focuses on how individuals form and change habits. The second section is about the habits of companies and organizations. And the third section is about the social implications of habits. Duhigg’s central thesis is that understanding how habits work makes it possible to change them. To write this book, he reviewed hundreds of studies and interviewed hundreds of scientists and businesspeople.
Duhigg emphasizes that his research is based on evidence—including both scientific research and real-world case studies of habit change. He also hopes to show that his book’s key principles apply to habits across a variety of different scales, ranging from individuals to society as a whole.
Duhigg’s interest in habits started when, as a reporter in Baghdad, he realized that the U.S. military is essentially just a huge habit-formation machine. It depends on teaching soldiers routines for how to think, act, shoot, and follow orders. In Iraq, the U.S. military also used habits to try and create peace. For instance, one army officer noticed that riots usually broke out after a crowd built up in a public plaza for several hours. He asked a small city’s mayor to ban food vendors in public plazas, and it worked: instead of staying all day and rioting, the next crowd of protestors got hungry and dispersed instead.
The U.S. military showed Duhigg what habits are good for: they make structured, repeated behaviors much more efficient and effective. He learned that, in addition to enriching individual lives, habit change can also make organizations—and entire countries—function more smoothly. By attacking habits instead of protestors, the Iraqi government managed to keep the peace without substantially infringing on people’s freedom to protest. While this technique is ethically debatable, it also shows how psychological manipulation can be a more effective and less disruptive way to exercise power than conventional means, like military force.
The army officer Duhigg interviewed explained that his entire military career was about forming habits. Having built his entire life around controlling his habits, he learned that they could change entire organizations and societies. Moreover, he was confident that everyone is capable of such change. Now, Duhigg points out, scientists know more about habits than ever before. Transforming these habits isn’t always simple, but it’s definitely possible—and science can show how.
The army officer represents the ideal of a composed, effective person who is fully in charge of their own habits—and therefore makes the best possible use of their time and abilities. Duhigg clearly implies that his readers can become this kind of person over time, if they follow his advice and learn to take control of their habits.