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Expert Advice

Why Is It So Hard to Break a Bad Habit?

By Brandon Ambrosino
Susan Courtney is a professor and chair of the Department of Psychological and Brain Sciences in the Johns Hopkins University Krieger School of Arts and Sciences.

The great English writer Samuel Johnson once said, “The chains of habit are too weak to be felt, until they are too strong to be broken.”

Most of us can attest to that. From the kinds of clothes we put on in the morning to how much sugar we take in our coffee, humans are creatures of habit.

And that’s a good thing. Well, most of the time, explains Susan Courtney. “Habits allow us to do things quickly and efficiently,” she says, “to get the things we want and to avoid the things we don’t want, without using a lot of resources for making decisions.”

Though you might not think of them this way, you rely on habits to successfully get through your day. As Charles Duhigg writes in The Power of Habit, “Without habits, our brains would shut down, overwhelmed by the minutiae of everyday life.”

But let’s back up for a minute. What exactly is a habit? “Habits are generally considered things that you do automatically when in a particular situation, or in response to a particular image or sound,” says Courtney. A habit is something that has been learned through repeatedly performing an action. Of course, just performing a behavior doesn’t make it a habit, she adds. “But if you perform that behavior regularly in response to a particular situation, such that whenever you are in that situation you have a tendency to do that behavior as a default, then it is a habit.”

There’s an old adage, Courtney says. “Neurons that fire together, wire together.” In other words, if the neurons that respond to a particular image or sound frequently fire at the same time as the neurons that cause you to do a particular behavior, the connections between those neurons will become stronger.

These connections strengthen if you receive a reward for performing a behavior. “A reward is the stuff we get that’s good,” she says. “That can be all sorts of things: money, good-tasting food, even the faces of attractive people.”

When we get rewards, Courtney says, our brains release dopamine, which facilitates the building of connections between brain cells.

“Each time you do something and you get a reward and those circuits in the brain become stronger, you’re more likely to do it again the next time you encounter that situation.” Because the brain is continually computing expectations, it can think that if a thing was rewarding in the past, it will be again.

This process, Courtney says, starts off consciously. You might eat a food and enjoy it, so you want to eat it again. That’s not yet a habit. “It becomes a habit when you no longer have to expect a reward from eating the food,” she says. “You eat the food because you’ve always eaten it.”

How quickly a person learns a habit depends on a few different things, like the strength of a particular reward and the regularity with which an action is performed. “A habit will grow stronger and faster, for example, if it’s done exactly the same each morning,” she says.

But if you perform any behavior and get rewarded for it often enough, you will eventually come to perform that behavior even if you’re not expecting a reward.

So, what if you’ve developed a bad habit—going to bed too late or eating a doughnut every morning—how do you go about breaking it?

“In order to do something different, you have to activate a different part of the brain to override those habitual tendencies,” says Courtney. “That’s the prefrontal cortex. It keeps track of your current situation and goals, and how they might be different from what they were before.”

The problem with the prefrontal cortex, she says, is it’s easily distractible and doesn’t work well when you’re stressed or tired. “When that part of the brain is vulnerable, those habits that are hardwired into the other parts of the brain automatically take over.”

To combat this, you might try giving yourself a physical reminder that you are trying to change a habit. That way, your prefrontal cortex isn’t tasked with remembering what you’re trying to change. Perhaps, she suggests, you bring a different wallet to the store to remind yourself that you’re not supposed to be spending too much. Or you hide your phone so you’re not seeing it all the time. There’s another thing you can do to curb a habit, and it’s much more effective in the long run: develop new ones.

“If you go to a doughnut shop every morning, try going to a farmer’s market instead. The first time you do that, it’s going to be really hard because you have to remember to go in a different direction, and then you’ll have to find something there that tastes as good as the doughnut. It’s going to be difficult until you find something you enjoy at the new place.”

Once you find a new rewarding thing, it gets easier. Before you know it, she says, you’ve replaced the bad habit with a better one. “The new habit overwrites the old one in your brain, so you don’t use the prefrontal cortex all the time.”

While Courtney studies the brain and habits for a living, she doesn’t pretend to always be successful at cultivating new ones for herself. “Habits are hard for everyone, but I do have strategies to help. I set up reminders, and I hide the things I don’t want to trigger habits. I put the chocolate in the cupboard.”

She also turns off her radio when she’s driving to a new place to allow herself to actively think about where she’s going. Whenever she attempts something new, she tries to eliminate distractions. “If my prefrontal cortex is occupied with something else, I’ll just keep doing what I usually do.”

Any time you can eliminate the stimulus that drives the habit, you’re one step closer to overcoming it.

Illustration of a person's head with smaller people walking around it in a circle
Image above by Andrea Wan

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