A tool for breaking bad habits (and building good ones)

Every weekday morning when I roll out of bed, I put on workout clothes under the outfit I’ll wear to take my son to the bus stop. It’s an odd layering strategy, I’ll admit, but it serves a purpose: it removes one tiny barrier between drop-off and my workout. And over time, I’ve learned that every bit of friction matters.

This month, I’m thrilled to share a Q&A with USC psychologist Wendy Wood who is the world’s leading expert on habits. I last featured Wendy in this newsletter back in 2020, when we talked about how habits are formed. In our new conversation, we focus on one powerful but often overlooked tool for shaping our routines: friction.

But before we get to that Q&A, here are my monthly recommended listens, watches, and reads…

This Month’s Recommended Listens, Watches and Reads

• Use the “Great Lock-In” to Achieve Your 2025 Health Goals: I spoke with CNN about how the “great lock in” trend on social media can be helpful to anyone with goals left to achieve in 2025.

• Understanding Self-control: In the season finale of Choiceology, I spoke with my close friend and collaborator Angela Duckworth about the science of self-control. As a special bonus, Charles Schwab made a video of our complete conversation available here.

• An Interview with Nobel Laureate Richard Thaler and Alex Imas at Wharton: Angela Duckworth and I hosted Richard and Alex for a conversation about their new book, The Winner’s Curse, in front of over 300 Penn students, faculty and staff, and now you can watch our conversation on YouTube.

Q&A: A Tool for Breaking Bad Habits and Building Good Ones

This Q&A from Choiceology is with emeritus USC psychology Professor Wendy Wood, who is the best-selling author of Good Habits, Bad Habits. Here she discusses how we can use friction to our advantage when we want to break bad habits or build good ones.

Me: Wendy, to start, could you define “friction”?

Wendy: In physics, friction is what stops motion. For behavior, friction is what gets in the way of us doing a certain thing.

One example is distance—when things are further away from us, we’re just less likely to act on them. And that’s great for when you’re trying to stop yourself from eating donuts. Just don’t keep them in your house. But it’s a problem when you’re trying to get to the gym. People are less likely to go when the gym is far away. Usually, we don’t think about distance in terms of friction, but it is a determinant of our behavior.

Another example is time. Online sites know this well—they know that reducing the amount of time it takes to buy something is an important way to control friction. That’s why it usually only takes one click to make a purchase. If you have to click a couple of times, they lose customers.

Effort is also another kind of friction, and that’s sort of obvious. When something takes much more effort and energy from us, we’re less likely to do it.

Me: That was so clear, and I love those examples. Could you describe some of your favorite research showing that friction changes our decisions?

Wendy: Yeah, I have a couple. One is a study from the 1980s. The focus of this research was to control elevator use. It was in a four-story building, so most people could take the stairs, but most used the elevator instead. The researchers were trying to figure out how to stop people from taking the elevator so often. So they did what most of us would think of first—they put signs all over the elevator and around the stairs that said “Take the stairs. It’s healthier for you.” Or “Take the stairs. It’s good for the environment.” It had no effect.

So then, the researchers slowed the closing of the elevator door by 16 seconds. Remember I said that time is an important component of friction. Well, that delay cut elevator use by a third. And the great thing was that when the researchers put the elevator back to its original speed a month later, people kept taking the stairs because a month had been long enough for them to form that habit. So that showed us that friction can help people form long-term habits.

Me: That’s such an interesting study. I also really love the recent work you’ve done with Asaf Mazar. Could you describe that?

Wendy: Yeah, we conducted a survey of U.S. voters before and after the 2020 presidential election. And what we found is that when people were asked what would either help them or get in the way of them voting, they described a lot of personal things. Like, “I’m really a strong Republican. I really hate this candidate. I think it’s my civic duty.”

They described a lot of beliefs about voting that they thought would motivate them to vote. Very few people described what you’d think of as friction, like whether they needed to get childcare in order to vote, whether they owned a vehicle so they could get to the polls, or how much time they thought it would take for them to vote.

So people mentioned beliefs, but they didn’t mention friction very often. And then we assessed them after they had voted. And it turns out that beliefs and friction were about equally important in determining whether people voted. We think of voting as this thing we do because we’re committed, either to our country or to a political party. But friction is really important in determining whether people vote. We just overlook it. All of this speaks to the fact that we tend to overvalue agency and underestimate the influence of difficulties in our environment, like barriers that can stop us from doing things.

Me: I’m curious, what first got you interested in studying friction, especially given that we tend to underestimate its power intuitively?

Wendy: So, I study habits. And habits are notoriously difficult to change. You can change your attitudes; you can change your preferences. We’ve all had the experience of deciding we’re going to start eating more healthfully, we’re going to start saving money, or we’re going to start exercising. But these involve changing our habits. And changing intentions doesn’t change those behaviors very effectively. So, in trying to figure out how to best change well-established habits, friction is a great alternative to the kinds of change strategies we typically think of. Friction works directly on the behavior itself, and it works on habits just like it works on other behaviors—it makes them less likely. So one of the best ways to control your unwanted habits is to add friction, set some barriers in the environment. And probably the best example of this is the anti-smoking campaigns.

Since the last century, we’ve gone from 50% of Americans smoking to only 15%. And certainly, part of that is people’s understanding that smoking causes cancer. That became clear around the middle of the last century. But even more important is that the government instituted policies in the U.S. to make smoking more difficult.

They started putting taxes on cigarettes. They banned smoking in public places. They made it so you couldn’t pull cigarettes off the shelf at a store. You have to ask someone for them. And sometimes also show your ID to prove that you’re old enough to purchase cigarettes. So all of these things make purchasing and smoking a little bit more difficult. Not impossible—we’re not removing people’s ability to make choices—but we’re encouraging them to make a healthy choice, which is “don’t smoke.” And that has had tremendous impact, even on something that is as addictive as nicotine. So it’s a very broad influence on behavior, and it’s very powerful.

Me: What do you think our listeners should do differently now that they have a better understanding of how much friction affects our decisions and our habits?

Wendy: Be aware of the importance of the barriers and forces around you that affect doing what you want. To control behaviors sometimes involves controlling those forces. Think about how to make behaviors that you want to perform easier. And how to make behaviors that you don’t want to do a little bit harder. Adding friction won’t take away your ability to do the unwanted behaviors or force you to do the wanted ones, but it will influence the likelihood that you might.

This interview has been edited for clarity and length.

To learn more about Wendy’s work, listen to the episode of Choiceology where we dig into sludge and friction, or get a copy of her excellent book Good Habits, Bad Habits: The Science of Making Positive Changes that Stick.

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

Katy Milkman, PhD

Professor at Wharton, Host of Choiceology, an original podcast from Charles Schwab, and International Bestselling Author of How to ChangeP.S. Join my community of ~100,000 followers on social media, where I share ideas, research, and more: LinkedIn / Twitter / Instagram / BlueSky / Threads