Does it Really Take 21 Days to Build a Habit?

Falling Into Better Habits

Many of the usual rhythms I associate with the beginning of fall have been thrown out the window this September. Instead of meeting my new Wharton students face-to-face, I’m meeting them online. Instead of sending my son off to Pre-K, I’m helping him Zoom into a virtual classroom. But even in these strange and difficult times, September is bringing change. Daily routines are shifting. And that means an opportunity to craft new and better habits.

Habits are the focus of today's newsletter. But before I dive in, here is some other content you might enjoy...

Recommended Listens and Reads

  • The COVID19 Habits That Will Last: I recently weighed in on the debate about which shifts in our lives due to the pandemic are likely to last and which are likely to be short lived for The Atlantic, sharing some of my favorite research on what produces enduring behavior change.

  • Spoiled for Choice: On the second episode of our new Choiceology season, I talked with emeritus Swarthmore psychology professor and best-selling author Barry Schwartz about when facing an abundance of choice is paralyzing, when it isn’t, and how to protect yourself from the risk of choice overload.

  • The Benefits of Seeing the Finish Line: University of Chicago marketing professor Oleg Urminsky shared research-based insights with me about why feeling close to the finish line makes you push harder on any goal in this Scientific American article.

  • Pandemic Behavior Change: On Slate’s popular podcast, The Gist, I had the pleasure of chatting with guest host Annie Duke, a former poker champion, decision scientist and best-selling author of Thinking in Bets about pandemic behavior change.

Q&A: The Science of Habit

Today I’m sharing an interview I conducted for Choiceology about the science of habit with University of Southern California psychology professor, Wendy Wood. Wendy explained where habits come from and what science says about how to intentionally form good ones and break bad ones.

Me: What is the definition of a habit?

Wendy: When we repeat a behavior over and over and get a reward for it our minds learn over time to associate what we've done with the context in which we got the reward. So habits are a kind of a shortcut.

Imagine the first time you walked into your kitchen in the morning and started to make coffee. You had to think about what to do. But overtime, if you do it enough, making coffee becomes a habit. It becomes something you can do without even thinking. You walk into your kitchen in the morning and you see your coffee pot or your coffee machine and you automatically do the sequence of things that get you coffee, which in this case is the reward.

It's as if you’re on autopilot and you can do the same thing over and over without having to make a decision.

All mammals seem to form habits in the same way. We have comparable neural structures in our brains that support this kind of learning. So that's why you can train your dog using similar principles to the kinds of shortcuts we all use when we repeat a behavior over and over.

Me: What’s your favorite study about habit formation?

Wendy: Probably my favorite study on how habits are formed was one that we did in a local cinema where we showed the theater-goers a bunch of short movies and they rated how interested they were in the movies. Supposedly as compensation, we gave them boxes of popcorn. But, unbeknownst to them, some of the boxes were fresh and others had stale popcorn. Really stale popcorn. We had popped it a week earlier and kept it in plastic bags in our lab and then served it to these people. At the very end of the show we asked them how often they ate popcorn at the movies.

So we have these people watching these shorts. They got to eat popcorn and then at the end we weighed how much they ate. What we found is that people who didn't have habits to eat popcorn at the movies did just what you'd expect: They ate more of the fresh popcorn and tended to leave the stale popcorn. That makes sense. I mean that's rational behavior.

But people who said they almost always eat popcorn at the movies didn't respond in a very rational way. They ate the same amount of popcorn whether it was fresh or stale. At the end of the study when we ask people how much they liked the popcorn, people who had strong habits could tell us they hated the stale popcorn just like people who had weak habits. Everyone hated it. It was awful. But people with strong habits still ate the stale popcorn and that's the power of habit cueing. Once you've formed a habit, the cues are so strong that we tend to repeat the behavior even if it's not the thing we want to do right now.

When we took this experiment out of the context of the movie theater and showed people music videos in a lab room, people who had strong habits to eat popcorn in the movie cinema didn't act any differently than people with weak habits. It's really the cues of the movie theatre that were making them respond irrationally.

And that’s how habits are formed. We form habits by repeating behaviors in the same way in the same context, and getting a reward.

What happens is that your mind learns through repetition to associate what you did — the response you're giving it with cues in that context. The cues could be other people, they could be the physical environment you're in, they could even be the time of day, or some action you just did. All those cues get tied with your response in your mind.

Me: What does research tell us about how to break bad habits?

Wendy: Well, most people think that to break a bad habit they have to somehow gather enough willpower, make a strong enough decision, and form a clear intention to change their behavior. They rely on willpower to do it, but willpower is a really tough thing to rely on.

So people's go-to solution for changing habits is not always the most effective one. Habits don't change easily by willpower because habits are automated and we're not always aware of what the cues are or of the associations that are driving our behavior.

What does work to break a habit, it seems, is changing the environment we’re in, which can disrupt those cues. I could bring apples into the office so I have something ready to snack on when it gets to lunchtime and I might be thinking I should go get some donuts from the vending machine. If I have something else at the ready that will compete with my thoughts about donuts, and then I'll be better off. A new environment will be a better way to try to shift my behavior than just exerting willpower.

Me: Let’s talk about how to form good habits. How can we set ourselves up for success?

Wendy: Let me give you the example of my son. My older son is a very committed bike racer. He's such an enthusiast that he has races every weekend. So you'd think that would be enough motivation to keep training. But even he finds that he has to organize his environment in ways that make it easy for him to keep practicing. So he puts his bike trainer in the middle of his living room. That way he actually has to move it aside in order to sit on the couch when he comes home from work. Usually it's just easier for him to get on his bike and work out for an hour or an hour-and-a-half every night. And that's, I think, the recipe for forming a habit that you repeat — making sure that you set up the situation you're in so that the behavior is easy in that situation. And the other thing that you have to do is make sure you really like what you're doing. So if you hate going to the gym, you’re probably not going to form a habit for it because it's not rewarding to you. You have to find ways to add rewards which will lead to the release of dopamine in our brains that ties together the action with the pleasure that creates a habit.

Me: Is it true that it takes 21 days to form a new habit?

Wendy: Well, I think that the 21-day thing is pretty ridiculous. From what I can tell, the idea that it takes 21 days to form a new habit comes from a self-help book, an early one in the 1960s, and it actually referred to how long it takes to get used to changes in your appearance after plastic surgery.

It wasn't even about habits and it wasn’t based on any data that we can tell and it doesn't make logical sense. There's no set number of days or repetitions until you form a habit, because some habits are easy to learn, right? Things like remembering to take your keys with you. You set your keys by the door, you pick them up when you leave. It's pretty easy. Others are much more complex. Things like going to the gym, driving a car, typing on your keypad. All of those things are more complex.

Those kinds of complex behaviors are going to take much longer to learn and they're going to take much longer to become a habit.

To learn more about habits, check out Wendy Wood’s book Good Habits, Bad Habits: The Science of Making Positive Changes that Stick or listen to the episode of Choiceology about habits.

This interview has been edited for clarity and length.

That’s all for this month’s newsletter. See you in October!

Katy Milkman, PhD
Professor at Wharton and host of Choiceology, an original podcast from Charles Schwab

 
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