How Long Does It Take to Form a Habit?

Let’s say that you decide that every night before you go to bed, you’ll walk around your house and clean up anything that’s out of order: you put any last dishes in the dishwasher, pick up any dirty clothes, shelve any books that are lying around, etc., so that in the morning you can wake up to an ordered house, because you find that makes you happier to start the day. You do it for a few days. You’re very proud of yourself. Then you’ve been doing it for a week. Then you’ve been doing it for a month, all without missing a day. Is that enough for it to be a habit? As usual, there’s a short answer and a long answer. The short answer is “probably not.” The long answer follows.

Science to the rescue: some hard numbers
I’m working from a single study, “How are habits formed: Modelling habit formation in the real world” by Phillippa Lally, Cornelia H. M. van Jaarsveld, Henry W. W. Potts, and Jane Wardle in the European Journal of Social Psychology, so we’re definitely talking about actual science here, but it’s just one study, so take this information as tentative for now. With that said, let’s plunge into the long answer.

The long answer is that there seems to be no set length of time it will take a person to develop a habit. Different people will take different lengths of time, and different habits will also take different lengths of time: for instance, it seems that complicated behaviors take longer to become habits than simple ones.

In the study I link to above, the range of time it took people to form habits (specifically, to “reach 95% of their asymptote of automaticity,” and if you don’t have to look up at least one word to understand that, you did better than I did) ranged from 18 days to 254 days, the average being 66 days. As a general rule of thumb, then, two or three months is often going to be enough time for something that you repeat daily to become a habit. According to the study, missing the habit just once in that time didn’t seem to cause trouble, though more than once did.

That long?
On the one hand, that’s depressing: that’s a long time to have to work that hard at something! On the other hand, this is great: in just two to three months, you can turn many behaviors into habits that you just do automatically without worrying much about them. Cleaning, answering letters in a timely fashion, speaking diplomatically, exercising, eating well–any one of these might well be within your grasp before Christmas. We already knew that habits don’t come automatically; this just gives us a better idea of how much work they take.

A little help from Kaizan
If you’d like a little help with keeping a habit, Kaizan has a good tip for helping habits not break down: How to Make Sure That Nothing Gets Between You and Your Good Habits.

In the comments to that post, someone cites an often-repeated piece of information that it takes 28 days to form a habit. I’ve heard this more than once, but never heard that it was based on any reliable research. My guess is that it’s meant to be inspirational guesswork, and since people like round figures so much, it caught on. I’ve also heard 21 days cited; don’t believe that one either. In any case, the comment drove me to find research that gives something more like a real answer to the question, which led me to Lally, et al.’s study.

Don’t get too attached to a number
We’ll want to try not to get too wrapped up in a specific number of days, like this article, where they seize on that 66-day average and proclaim it as a universal truth. However much we human beings like a simple, unchanging answer, 66 days is just an average: your mileage is extremely likely to vary.

Why it doesn’t always matter
And it may help to act as though habit formation won’t be happening at all, to simply use feedback loops to keep up good practices and make good choices, and to take habit formation as a wonderful accident. As with any other positive development that results from being motivated, habit formation causes problems if it’s thought of as the end goal: it’s essential to find things to enjoy about the steps along the way in order to keep up anything important long enough for it to matter.

Photo by .scarlet.