“It only takes 21 days to make a new habit stick.” Sounds simple enough, right? But is this really accurate? Find out whether there is scientific truth to this statement, and what we might expect instead.

The daily habits we adopt - both big and small - are the defining factors that determine whether we thrive or become worse off as we age.

The choices that we make include the food we eat, the amount we move our bodies, and  the substances we use. One by one these choices add up and collectively influence the state of our overall health.

Healthy habits are certainly not formed overnight. Anyone who has tried to instill a new, healthy habit knows all too well that it can be challenging, to say the least, and that it is often tempting to throw in the towel during the process.

The myth of “21 days”

How long does it take to break a bad habit and adopt a new one?

Conventional wisdom, as championed by many behavioral change experts, has us believing that it takes around 21 days to ditch an old habit and replace it with a new one.

But it turns out that this premise is just a myth, an idea based on a non-scientific observation expressed by a physician in his 1960 book, Psycho-Cybernetics, that spread like wildfire. Cosmetic surgeon Dr. Maltz, in fact, only observed that his patients seemed to adjust to their new facial and bodily changes after a minimum of 21 days.  This lone observation was not about habit formation at all, but rather about the time it took his patients to accept their new looks. But as the book rose in popularity, so did this “21-day” misconception, and it was quickly related to habit formation and accepted as fact.

More recent science shows, however, that in reality it can take much longer than that.

How long does it take to break and build a habit?

A 2009 study and a 2021 study more accurately shed light on the true nature of how long it takes to scrap an old habit or establish a new one.

In the 2009 study, 96 participants were asked to adopt new exercise routines as well as new healthy eating and drinking regimens over 12 weeks. The scientists observed that it took between 18 and 254 days, with an average of 66 days, of the new repeated behaviors to become automatic.

The 2021 study reached a similar finding. In it, researchers analyzed the habit formation behaviors of 192 adults who attempted to link a new healthy behavior with their daily routine, like drinking water while watching the news or stretching first thing in the morning.  They found that it took the subjects an average 59 days to solidify their new habit.

The type of habit makes a big difference

As the above studies show, the average time it takes to truly start a new habit ( or break an old one) is at least two months, which is dependent on a variety of reasons that cause some individuals to adopt habits faster than others.

What matters more when it comes to habit formation is the type of habit involved.

Some habits are simply easier to stick to than others.

For example, it is not too much of a stretch to commit to drinking a glass of water after just waking up every morning. But jogging for 20 minutes on the treadmill before work each day? That takes a lot more time and perseverance.

Autonomous motivation vs. controlled motivation

Not only is the kind of habit significant as it relates to how quickly it can be adopted, but the type of motivation that is driving the habit is important as well.

Researchers have identified two different types of motivation that influence our taking on new behaviors: autonomous motivation and controlled motivation.

Take exercising as an example.

Someone who inherently understands the benefit of being active and personally enjoys it has the autonomous motivation to exercise. They do not need to be convinced to adopt this new habit.

On the other hand, someone who has just been cautioned by their doctor to exercise to improve their health might only exercise out of obligation, or by controlled motivation, and not because they genuinely appreciate the value of it.

Not surprisingly, research shows that autonomous motivation is the more effective and influential of the two.  Those who begin a new habit autonomously already recognize the value of the work they are putting in, and are way more likely to stick with it in the long run.

The habit loop: how new habits are reinforced

There’s a reason the phrase “old habits die hard” holds so much weight. It turns out that there is a neurological explanation for why we get so caught up in unhealthy habits we cannot seem to break.

Researchers at MIT have discovered that at the heart of every habit, a simple and predictable loop exists, a loop that consists of a cue, a routine, and a reward.

For example, let’s say around 3PM during the afternoon slump of the workday, you start to crave a sweet snack. You get out of your chair, walk over to the vending machine, and purchase a large bag of cookies to eat. Only, this purchase is not isolated to one day.  It is a habit you have established every workday for the past year - and your waistline most definitely shows it.

Here, the cue is the time of day (3PM afternoon slump), the routine is buying a bag of cookies, and the reward is a jolt of energy as a pick-me-up when you start to feel sluggish.

Want to ditch your own bad habit or two?

Start by identifying the elements of your loops. Once you can recognize the cues, routines, and rewards that are at play, you can look for ways to replace old unwanted behaviors with more productive ones.

The key takeaway

Our daily habits are primary factors that determine how well we live now and as we age, and the ways in which we form those habits determines our actual ability to change our behavior. “Conventional wisdom” has many of us believing that it takes 21 days to form a new habit. But, as it turns out, evidence shows that it can take much longer for a new behavior to stick. If you are trying to adopt a healthier habit and are finding it taking longer than you expected, do not get discouraged. The most important thing is to keep at it until it finally becomes an automatic part of your routine, whenever that may be.