The Power of Habit: Why We Do What We Do in Life and Business by Charles Duhigg

neurological roots of the habit loop. After all, it would be another seventy years before the MIT scientists and Wolfram Schultz conducted their experiments.

    So how did Hopkins manage to build such a powerful toothbrushing habit without the benefit of those insights?

    Well, it turns out that he actually
did
take advantage of the principles eventually discovered at MIT and inside Schultz’s laboratory, even if nobody knew it at the time.

    Hopkins’s experiences with Pepsodent weren’t quite as straightforward as he portrays them in his memoirs. Though he boasted that he discovered an amazing cue in tooth film, and bragged that he was the first to offer consumers the clear reward of beautiful teeth, it turns out that Hopkins wasn’t the originator of those tactics. Not by a long shot. Consider, for instance, some of the advertisements for other toothpastes that filled magazines and newspapers even before Hopkins knew that Pepsodent existed.

    “The ingredients of this preparation are especially intended to prevent deposits of
tartar
from accumulating around the necks of the teeth,” read an ad for Dr. Sheffield’s Crème Dentifrice that predated Pepsodent. “Clean that dirty layer!”

    “Your white enamel is only
hidden
by a coating of film,” read an advertisement that appeared while Hopkins was looking through his dental textbooks. “Sanitol Tooth Paste quickly restores the original whiteness by removing film.”

    “The charm of a lovely smile depends upon the beauty of your teeth,” proclaimed a third ad. “Beautiful, satin smooth teeth areoften the secret of a pretty girl’s attractiveness. Use S.S. White Toothpaste!”

    Dozens of other advertising men had used the same language as Pepsodent years before Hopkins jumped in the game. All of their ads had promised to remove tooth film and had offered the reward of beautiful, white teeth. None of them had worked.

    But once Hopkins launched his campaign, sales of Pepsodent exploded. Why was Pepsodent different?

    Because Hopkins’s success was driven by the same factors that caused Julio the monkey to touch the lever and housewives to spray Febreze on freshly made beds. Pepsodent created a craving.

    Hopkins doesn’t spend any of his autobiography discussing the ingredients in Pepsodent, but the recipe listed on the toothpaste’s patent application and company records reveals something interesting:Unlike other pastes of the period, Pepsodent contained citric acid, as well as doses of mint oil and other chemicals. 2.31 Pepsodent’s inventor used those ingredients to make the toothpaste taste fresh, but they had another, unanticipated effect as well. They’re irritants that create a cool, tingling sensation on the tongue and gums.

    After Pepsodent started dominating the marketplace, researchers at competing companies scrambled to figure out why. What they found was that customers said that if they forgot to use Pepsodent, they realized their mistake because they missed that cool, tingling sensation in their mouths. They expected—they
craved—
that slight irritation. If it wasn’t there, their mouths didn’t feel clean.

    Claude Hopkins wasn’t selling beautiful teeth. He was selling a sensation. Once people craved that cool tingling—once they equated it with cleanliness—brushing became a habit.

    When other companies discovered what Hopkins was really selling, they started imitating him. Within a few decades, almost every toothpaste contained oils and chemicals that caused gums to tingle. Soon, Pepsodent started getting outsold. Even today, almost alltoothpastes contain additives with the sole job of making your mouth tingle after you brush.

    THE REAL PEPSODENT HABIT LOOP

    “Consumers need some kind of signal that a product is working,” Tracy Sinclair, who was a brand manager for Oral-B and Crest Kids Toothpaste, told me. “We can make toothpaste taste like anything—blueberries, green tea—and as long as it has a cool tingle, people