Breaking a habit generally involves forming a new one. But as anyone who’s tried quitting smoking can attest, that’s easier said than done. Part of the reason is that breaking a habit takes a long time.

Despite what Linkin Park might have to say, you likely won’t be ‘breaking the habit tonight’. Instead, psychologists estimate it takes roughly 60 days to break or form a new habit. So, hang in there!

Tell me your habits and I’ll tell you who you are

Humans are creatures of habit — and frankly, we couldn’t possibly go through life sanely without them. However, not all habits are equal. Reading before bed and brushing your teeth every morning after you wake up are some great habits. Smoking a pack a day and watching TV until 2 AM, not so much.

Seeing how habits can make or break people, psychologists are very interested in them, with some considering shaping a person’s habits integral to their therapy practice.

Habits are behaviors that have become automatic through regular repetition. They tend to be performed subconsciously, which frees mental ‘bandwidth’ for other things.

When we perform a habitual action, we are far less engaged in the task compared to when we are doing something that is not a habit. Between the time you wake up and the time you go to bed, there are dozens if not hundreds of activities we perform almost mindlessly that follow a repeated pattern on a daily basis. In time, these reinforced actions can feel like they’re pushing us from behind to do them all over again the next day, and resisting performing these actions can feel uncomfortable.

How long does it actually take to make or break a habit?

In the 1950s, a plastic surgeon by the name of Maxwell Maltz began to notice that many of his patients took about 21 days before they got used to seeing their new face after an operation — like a nose job, for example.

Prompted by the observation of this peculiar pattern, Maltz looked inward, into his own life, and noticed that it also took about 21 days to adjust to a new house someone just moved into or even to the absence of a limb after amputation.

These experiences eventually led Maltz to publish his much-acclaimed 1960s book Psycho-Cybernetics, in which he states that “it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell.” The book sold more than 30 million copies and is still in print today.

This “21 days” figure has been repeated countless times ever since. It has been republished and rehashed in thousands of self-help books, seminars, and TV shows.

There’s a problem though. The “21 days” time window for cementing changes in habit is less a statistical fact and more like a myth.

Maltz never performed a rigorous study using the scientific method. His statistics are anecdotal, at best. But that doesn’t mean that there aren’t scientists who have made a genuine inquiry.

In 2009, researchers at the University of College London led by Phillippa Lally examined changes in the habits of 96 people over a 12-week period. Each person had to choose a new habit they wanted to internalize and reported each day on whether or not they had performed an activity related to the behavior and how routine it felt.

Some participants proposed some very simple habits for themselves, such as “drinking a bottle of water with lunch”, while others were more ambitious aiming for more challenging activities like “running for 15 minutes before dinner”.

After 12 weeks, the study came to a close and the researchers used statistical methods to interpret the data they had gathered. Their assessment blew Psycho-Cybernetics out of the water, showing that the time it took to form a new habit ranged from 18 to 254 days.

According to the researchers, this indicates “considerable variation in how long it takes people to reach their limit of automaticity and [highlights] that it can take a very long time.” After all, it just makes sense because each person’s motivation is different. Some are extremely driven to change their behavioral patterns, perhaps spurred by an intense emotional experience such as divorce or the birth of a child. Others are simply more disciplined, having the life practice and experience to help them overcome the various challenges that stand between you and your goals.

Personally, I think these findings are hugely important, especially in the context of arbitrary statistical figures such as “21 days” or “60 days”. Some people may feel discouraged once their supposed habit-forming timeframe expires and they’ve yet to make positive changes in their lives. However, being cognizant that each person is different and that the habit formation process may take a long time may actually be empowering.

Another useful finding was that missing a few days of engaging in a habit-forming process did not significantly affect the habit. In other words, it’s okay to mess up once in a while. If you just stick with the process, eventually you’ll form those positive habits you’re striving for.

“With repetition of a behaviour in a consistent context, automaticity increases following an asymptotic curve which can be modelled at the individual level,” the authors added in their study published in the European Journal of Social Psychology.

If a range is not to your satisfaction, the average number of days it takes for a new behavior to become ingrained in a routine is 66 days. In any case, that’s much longer than the 21 days often cited online and in self-help books.