How long does it take to form a new habit?

As I write this, it is approaching the end of New Year’s Day and Sarah and I are relaxing in a cute Airbnb in the historic area of downtown Savannah, Georgia. Savannah has always been one of our favorite cities and since we spent the holidays nearby, it was an easy choice as a place to welcome in 2020. This town knows how to throw a party, and downtown was alive and bumping.

Today my social media feed has been filled with the typical New Year’s posts—some people expressing optimism for the coming year, others fondly reflecting on the past 12 months, and others proclaiming their New Year’s resolutions to their Facebook friends. My own people give me the impression that the first week of January must be incredible for gyms, health food stores, and yoga studios. I would like to think these intended behavioral changes will be long-lasting—after all I am an optimist—and yet I know that by the time Valentine’s Day comes around most of these proclamations will be distant memories forgotten by everyone except Mark Zuckerberg, who will no doubt become even richer in the process.

As I tour the country doing what I do, I often discuss how the brain forms habits and why it is so hard to change some of them. We all know that despite our intentions, most of us will not stick to our new diet or continue exercising or follow through with whatever we set our mind to earlier. We will ultimately fail, just as we have so many times in the past. Long-term behavioral change is a difficult prospect for us, a reality we are aware of but seem to think there is a secret answer out there we just haven’t encountered yet. Like when a woman asked me if I had any tips on how to lose weight and I said," Eat less and exercise more,” she replied, “Yes, but anything else? I really like eating and I hate exercising.”

Habits are behaviors that our brain has learned to produce without thinking about it and making a resolution stick involves creating a new habit. There are behaviors we engage in automatically and there are those that require conscious effort. Imagine you are sitting on the couch trying to get motivated to go to the gym. You deliberate over the pros and cons, consider how much time you have, the other things you have to do, whether your gym clothes are clean, and how you will get there. If you have to think about a behavior, it is not a habit. In that situation, I bet you didn’t have to think about whether or not you sat on the couch, that behavior is a habit. There are people that go to the gym out of habit, so how can you become one of them and stay true to your Facebook post? Habits are learned through repetition, so the key to convincing your brain to head to the gym every day no matter what is going to require some forced repetition.

One of the most common questions people have for me is, how many repetitions does it take? There is a popular idea out there that it takes 21 days to make a habit. Assuming you engage the new behavior every day, a three-week commitment seems pretty manageable. By Martin Luther King day we should all be habitually exercising and eating kale. Unfortunately, that 21 days idea is a myth. The same is true if you’ve heard it takes 30 days or any other number of days. I know there are popular books out there that suggest the contrary, but anyone who makes a general claim like that is lying: There are too many unknown variables, and so it is simply an incalculable equation.

One of the variables is the reward value of the behavior. Not that I have personal experience, but I am pretty sure it does not take 21 days of smoking crack to develop a crack habit. Legalities aside, it has got to be way easier to launch a crack habit than a gym habit. Anything that provides our brain with intense feelings of pleasure is going to be learned fast, which is why many of us already have a set of habits we’d like to change to begin with. On the other hand, for most of us going to the gym is not immediately pleasurable and it’s going to take a lot of work to habituate that behavior. Another is the reward value of our pre-existing habits. Chances are that our brain has already learned a lot of highly rewarding habits and those are stiff competition for the new thing we are trying to learn. Also, how complicated is the behavior? Simple behaviors are easier to habituate than more complex behaviors. Sitting on the couch is incredibly easy, especially when the alternative is getting our butt in the car and driving that car to the gym to work out.

At the point in our life where we decide we need to make a New Year’s Resolution, chances are we have already learned all of the simple, highly rewarding habits we are willing to take on. Any lasting behavioral change from this point forward is going to take work, and a lot of repetitions.

So, these estimates are wrong but I think they still hold value. They are psychological placebos and can be motivating. If you go to the gym for 21 days in a row what do you think you will do on day 22? You’ll probably end up at that gym. It may still be a struggle to get there, but you’ll likely keep going out of routine if not out of habit. And eventually, maybe, it’ll be something you do automatically.

Here’s to you in 2020.