Hooked: How to Build Habit-Forming Products

by Nir Eyal

Our brains have evolved over millennia to help us figure out how things work. Once we understand causal relationships, we...

However, when something breaks the cause-and-effect pattern we’ve come to expect—when we encounter something outside the norm—we suddenly become aware of it again.

Novelty sparks our interest, makes us pay attention, and—like a baby encountering a friendly dog for the first time—we seem to love it.

I propose that variable rewards come in three types: the tribe, the hunt, and the self.

Our brains are adapted to seek rewards that make us feel accepted, attractive, important, and included.

Bandura studied the power of modeling and ascribed special powers to our ability to learn from others.

that people who observe someone being rewarded for a particular behavior are more likely to alter their own beliefs and subsequent actions.

this technique works particularly well when people observe the behavior of people most like themselves or who are slightly more expe...

The uncertainty of what users will find each time they visit the site creates the intrigue needed to pull them back again.

variable content

ti...

“Like” button provides a variable reward for the co...

Stack Overflow devotees write responses in anticipation of rewards of the tribe. Each time a user submits an answer, other members have the opportunity to vote the response up or down.

When they reach certain point levels, members earn badges, which confer special status and privileges.

Yet on Stack Overflow, points are not just an empty game mechanic; they confer special value by representing how much someone has contributed to his or her tribe.

“Quadrupeds cannot pant and gallop at the same time.”

After being tracked for a sweltering eight hours under the African sun, the beast is finally ready to give up, collapsing in surrender with barely a struggle. The meager hundred-pound San hunter outlasts the powerful five-hundred-pound beast with little more than his persistence and the biomechanical gifts evolution has given him. The hunter swiftly and ceremoniously kills his prize, piercing a vein in the animal’s neck so that he can feed his children and his tribe.

Our ability to maintain steady pursuit gave us the capacity to hunt large prehistoric game. Yet persistence hunting was not only made possible because of our bodies; changes in our brains also played a significant role.

The need to acquire physical objects, such as food and other supplies that aid our survival, is part of our brain’s operating system.

The Twitter timeline, for example, is filled with a mix of both mundane and relevant content.

This variety creates an enticingly unpredictable user experience.

To keep them searching and scrolling, the company employs an unusual design. As the user scrolls to the bottom of the page, some images appear to be cut off.

However, these images offer a glimpse of what’s ahead, even if just barely visible. To relieve their curiosity, all users have to do is scroll to reveal the full picture (figure 22).

The rewards of the self are fueled by “intrinsic motivation” as highlighted by the work of Edward Deci and Richard Ryan. Their self-determination theory espouses that people desire, among other things, to gain a sense of competency. Adding an element of mystery to this goal makes the pursuit all the more enticing.19

Their self-determination theory espouses that people desire, among other things, to gain a sense of competency. Adding an element of mystery to this goal makes the pursuit all the more enticing.19

Have you ever caught yourself checking your e-mail for no particular reason? Perhaps you unconsciously decided to open it to see what messages might be waiting for you. For many, the number of unread messages represents a sort of goal to be completed.

Users can give up when they sense the struggle to get their in-boxes under control is hopeless. To combat the problem and give users a sense of progress, Google created “Priority Inbox.”20

game. The interactive lessons deliver immediate feedback,

But over time, users began to lose interest. Although the payout of the bounties was variable, somehow users did not find the monetary rewards enticing enough.

In Mahalo’s case, executives assumed that paying users would drive repeat engagement with the site. After all, people like money, right? Unfortunately, Mahalo had an incomplete understanding of its users’ drivers.

Quora instituted an upvoting system that reports user satisfaction with answers and provides a steady stream of social feedback.

Only by understanding what truly matters to users can a company correctly match the right variable reward to their intended behavior.

Points, badges, and leaderboards can prove effective, but only if they scratch the user’s itch.

In an effort to increase user engagement, Quora introduced a new feature, “Views,” which revealed the real identity of people visiting a particular question or answer. For users, the idea of knowing who was seeing content they added to the site proved very intriguing.

However, the feature backfired. Quora automatically opted users in to the new feature without alerting them that their browsing history on the site would be exposed to others. In an instant, users lost their treasured anonymity when asking, answering, or simply viewing Quora questions that were personal, awkward, or intimate.

We’ll address the morality of manipulation in a later chapter—but aside from the ethical considerations, there is an important point regarding the psychological role of autonomy and how it can impact user engagement.

The magic words the researchers discovered? The phrase “But you are free to accept or refuse.” The “but you are free” technique demonstrates how we are more likely to be persuaded to give when our ability to choose is reaffirmed.

The researchers believe the phrase “But you are free” disarms our instinctive rejection of being told what to do.

However, when a request is coupled with an affirmation of the right to choose, reactance is kept at bay. Yet can the principles of autonomy and reactance carry over into the way products change user behavior and drive the formation of new user habits?

My only options were to comply or quit; I chose the latter.

that the most successful consumer technologies—those that have altered the daily behaviors of billions of people—are the ones that nobody makes us use.

Perhaps part of the appeal of sneaking in a few minutes on Instagram or checking scores on ESPN.com is our access to a moment of pure autonomy—an escape from being told what to do by bosses and coworkers.

Companies fail to change user behaviors because they do not make their services enjoyable for its own sake, often asking users to learn new, unfamiliar actions instead of making old routines easier.

Companies that successfully change behaviors present users with an implicit choice between their old way of doing things and a new, more convenient way to fulfill existing needs.

By maintaining the users’ freedom to choose, products can facilitate the adoption of new habits a...

people often feel constrained by threats to their autonomy and rebel. To change behavior, products must ensure the users feel in control. People must want to use the service, not feel they have to.

At the heart of every episode—and also across each season’s narrative arc—is a problem the characters must resolve.

Challenges prevent resolution of the conflict and suspense is created as the audience waits to find out how the story line ends.

By design, the only way to know how Walter gets out of the mess he is in at the end of the latest episode is to watch the next episode.

The cycle of conflict, mystery, and resolution is as old as storytelling itself, and at the heart of every good tale is variability.