Early in the 20th century, the inventor of a minty new toothpaste called “Pepsodent” called up the wealthy advertising executive Claude C. Hopkins to ask for help designing a marketing campaign. Hopkins was famous for his outlandish claims promoting products like Palmolive soap and Quaker Oats. He also wrote an influential set of rules for getting consumers to develop new habits. But he wasn’t interested in Pepsodent because almost nobody in the U.S. brushed their teeth. But his inventor friend eventually convinced him to give Pepsodent a shot.
Hopkins applied habit change in a way completely different from Lisa Allen or Eugene Pauly. Namely, he manipulated other people’s habits in order to sell more of his products. Needless to say, this kind of manipulation is central to modern marketing and explains why businesspeople are likely to find Duhigg’s book valuable. Hopkins’s work also shows that habit change isn’t just individual: it can also happen on a mass scale, by getting thousands or millions of people to form the same cue-routine-reward loop.
Hopkins’s secret to selling Pepsodent was creating a craving. He always looked for a “trigger” that would get consumers to use products. After learning about the harmless natural film that builds up on the teeth, he started putting up ads that told people to run their tongue across their teeth and feel the dirty film—which Pepsodent would remove. The cue was the film, the routine was tooth-brushing, and the reward was a cleaner, more beautiful smile.
While Hopkins was working long before modern research found the habit loop’s neurological basis in the brain, he still knew how to use it to sell his products. His ads taught consumers to recognize the cue (dirty teeth) and associate the reward (clean, beautiful teeth) with the use of his product. If he hooked his consumers on the tooth-brushing routine, then they would make a habit out of using—and buying—his product.
In three weeks, Pepsodent was sold out. A few years later, Pepsodent was selling all around the world, and most Americans were regularly brushing their teeth. Hopkins’s ad campaign succeeded because he followed two basic rules: he found a straightforward, basic cue and “clearly define[d] the rewards.” These two rules are the keys to advertising and habit formation today. But there’s also one more rule.
Hopkins’s campaign shows how effective mass habit change can be—and also how it can benefit the public, particularly in situations involving public health. As Duhigg pointed out in the last chapter, habit loops tend to be very delicate, so it makes sense that Hopkins succeeded by making the habit loop specific, clear, and consistent—this made it much easier for consumers to fall into the loop, and reinforce it over time.
In 1996, scientists and marketers at Proctor & Gamble were struggling to plan an ad campaign for a new smell-neutralizing spray based on the compound HPBCD. It was called Febreze. Drake Stimson, a former Wall Street mathematician, led the marketing campaign. When they test-marketed their product in Phoenix, they met a park ranger whose job was to capture skunks. As a result, everything in her house smelled like skunk. She said that Febreze changed her life. Stimson realized that Febreze could be a way for people to eliminate “embarrassing smells,” and his team designed ads that showed Febreze getting rid of cigarette and pet odors.
Stimson and his team faced a similar challenge as Hopkins: how could they get consumers to turn Febreze into a habit? Their first instinct was to market Febreze to people whose lives were affected by bad smells. Arguably, this could turn into a habit routine: the cue would be foul smells, the routine would be using Febreze, and the reward would be a pleasant-smelling house. But while this was Febreze’s true purpose, this wasn’t necessarily the way to make it catch on or sell.
But the ads didn’t work. Febreze barely sold—even people who received free samples never used it. Drake Stimson almost got fired. But then Proctor & Gamble agreed to hire more consumer psychologists and give the campaign one more try. They visited another Phoenix woman’s home that stunk horribly like cats. But the woman couldn’t smell it. They realized that this was the problem: people usually get used to the bad smells they live with, to the point that they can’t smell them anymore. Therefore, they never made a habit of using Febreze. This left Stimson’s team with a serious problem: if people with stinky homes wouldn’t buy Febreze, who would?
Although Stimson tried to set up a habit loop for Febreze, he failed because few people actually noticed the cue of foul smells. Instead, they were already used to those smells. Again, unconscious, automatic habits actually prevented people from taking the steps that would improve their lives. Thus, Stimson’s team had to find a way to make people crave a product that they didn’t know they needed. This shows how difficult it can be to develop new habits, even when they’re obviously beneficial.
While studying monkeys’ brains in the 1980s, the Cambridge professor Wolfram Schultz noticed that some monkeys liked apple juice, while others liked grape juice. He made a monkey named Julio play a game: he had to press a lever whenever a shape appeared on a screen. If he did, he got blackberry juice as a reward. At first, Julio’s brain activity spiked whenever he got the juice. Over time, however, it started to spike as soon as he saw the shapes, well before he got the juice. In other words, Julio started to anticipate his reward.
Schultz’s experiments show how primates (like monkeys and humans) develop cravings by detecting patterns over time. As they learn to associate the rewards of a routine with the cue that triggers that routine, they start to proactively perform the routine in response to the cue, because they expect the reward. Thus, while at first people (or monkeys) might perform a habit either because they have to or because they force themselves to, over time, cravings make them actually want to perform it.
Then, Wolfram Schultz changed the experiment so that Julio only sometimes got juice. Whenever he pushed the lever but didn’t get his juice, Julio started responding with anger or depression. He was craving the juice. When monkeys in the same experiment had the opportunity to leave and eat food or play with other monkeys, they tended to do so—unless they had already started to develop cravings, in which case they kept pressing the lever indefinitely, like a gambler at a slot machine.
Julio’s decision to continue playing the game is very significant: it shows that he became addicted. While this clearly shows why negative habits like gambling and drug use can be so dangerous, it’s also instructive for people who hope to develop positive habits over time. Namely, it shows that they have to anticipate and crave rewards enough that they actively seek out the habit. Otherwise, they can easily abandon or forget the new habit they wish to form.
Wolfram Schultz’s experiment showed that habits’ power comes from their ability to build cravings over time, as they cause individuals to associate specific cues with specific rewards. For instance, over time, Julio started to immediately crave the juice as soon as he saw the cue (the shapes on the screen). Similarly, smokers start craving nicotine as soon as they see a pack of cigarettes, and people start anticipating opening their email as soon as they hear a notification sound. When particularly strong, craving can lead to addiction. But it’s still possible to overpower.
One of the most common obstacles to habit change is that people lack the motivation to improve. But Schultz’s research shows that, once people learn to crave the reward associated with a habit, they become intrinsically motivated to pursue the habit. Therefore, it’s possible for people to build a habit simply by forcing themselves to repeat it over and over, until they start to actually desire its reward.
Physical exercise provides a good example of the relationship between craving and habit. A New Mexico State University study showed that most habitual exercisers keep going because they crave the endorphins and the feeling of accomplishment that working out gives them. To build a lasting habit, people must create simple cues and clear rewards for themselves—but the cue also needs to make them start craving the reward in order to really work. Wolfram Schultz told Duhigg that cues, rewards, and cravings can even lead people to develop habits they don’t want (like snacking on their children’s chicken nuggets at dinner). But cues, rewards, and cravings are also the key to building good habits.
The importance of cravings runs contrary to the general wisdom about habit change, which says that discipline is the key to building new habits. While discipline might help people build cravings in the first place, it’s not what keeps them going. Thus, while the common wisdom encourages people to deny and repress their feelings in order to improve, Duhigg suggests that people should instead acknowledge and embrace these feelings. In other words, rather than trying to overcome the habit loop, people should use it to their advantage.
After their first marketing campaign for Febreze failed, Drake Stimson and his team started desperately looking for other angles. Back in Phoenix, they visited a third woman. Even though she wasn’t trying to neutralize any specific smell, she sprayed Febreze in her house every day. She used it “as a final touch” to make things smell good every time she finished cleaning a room. She treated it as “a little mini-celebration.”
The Phoenix woman’s use of Febreze shows that people always seek rewards at the end of their routines. In their earlier research, Stimson’s team assumed that Febreze would be the routine in a habit loop, but their market research showed them that it could function better as the reward. Rather than helping people with smelly houses clean those houses, Febreze would be a way for people who already cleaned their houses to feel a sense of accomplishment.
Back at the company headquarters, the marketing team analyzed video footage and realized that almost everyone looks happy after cleaning. They decided that Febreze should be the last part in a routine, a reward promising that “things will smell as nice as they look” after cleaning. Surely enough, consumers started craving the smell of Febreze, and sales skyrocketed. This again showed that simply creating cues and rewards wasn’t enough—ads also needed to create cravings. This is the third element that Claude C. Hopkins forgot about.
Ironically, although Febreze started out as an innovative new odor-eliminating compound, it ended up being marketed for an entirely unrelated purpose. People didn’t buy Febreze until they had a reason to crave it—and this craving ended up being more important than Febreze’s actual function. This suggests that habits are one of the prime drivers of consumer behavior—which again explains why they are so important to businesspeople and marketers.
Despite his wild popularity, Claude C. Hopkins never identified the value of cravings. But this was the real reason he sold so much toothpaste. In reality, dozens of toothpaste companies besides Pepsodent had already promised to remove the film and reveal a beautiful smile in their advertisement. But Pepsodent contained chemicals like mint oil and citric acid, which left “a cool, tingling sensation” in people’s mouths after they used it. This created a craving. Over time, other companies copied Pepsodent, and today, most toothpastes contain cooling additives.
Hopkins thought that people were addicted to the feeling of not having film on their teeth. But in reality, Duhigg suggests, they were addicted to the pleasant tingling sensation that they associated with using the product. Thus, Pepsodent made toothbrushing seem more rewarding than it would have been otherwise. This elevated, in-your-face reward was what created true cravings: it clearly showed users that the product was benefiting them and gave them something to look forward to the next time they used it.
Duhigg concludes that cravings are the key to building habits. They’re the reason why most people brush their teeth but don’t use sunscreen on a daily basis. Cravings are also why business make shampoo, laundry detergent, and toothpaste that foam up—something consumers apparently crave. If they want to build new habits, people have to learn how to spark new cravings first.
Duhigg’s analysis of cravings suggests that people don’t really adopt habits because they know that those habits will benefit them. Instead, they adopt habits when they become attached to the immediate reward associated with completing them. It also helps when cues are very consistent, because this allows people to clearly predict the reward every time. Thus, to develop new habits, people shouldn’t just convince themselves that those habits are good for them—instead, they should reward themselves consistently enough to start craving the habit.