There’s no ‘magic number’ for forming a new habit, says study

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Mental Health


There’s no ‘magic number’ for forming a new habit, says study

By Ellen Scott

2 years ago

2 min read

How long will it take to form a habit that sticks? It depends on what it is.

How many times have you heard that you need to do something for 40 days before it becomes a habit? Or is it 21 days? Or two weeks? Or 70 days? 100? 

There’s a lot of conflicting information out there, but the general message is this: there’s a ‘magic number’ for how long you need to persist with a task to transform it into a routine that sticks. If you can just reach that magic number, we’re told, you’ve done it. The habit is set. 

But that might be all wrong, at least according to a new study

Researchers found that how long it takes to form a habit depends on a bunch of different factors, including what the habit actually is. Getting into the habit of going to the gym, for example, took an average of – brace yourselves – six months. To form the habit of hand-washing, however, required just a few weeks. 

The study tracked gymgoers at 24 Hour Fitness and healthcare workers who were tasked with wearing special badges that tracked how often they washed their hands. In the case of the gym people, they found that certain factors played a bigger role than you might think. Rather than having to go every day for 21 days, for example, it may be more important to just not skip too many days in a row. For 76% of the participants, the amount of time that had passed since their last gym trip was a big predictor of whether they went again. 

Neither group suggested there’s a magic number – whether that’s 21 days, 40 or 70 – for how many days to do something to make the habit stick. 

“You may have heard that it takes about 21 days to form a habit, but that estimate was not based on any science,” said Colin Camerer, one of the researchers. “Our works supports the idea that the speed of habit formation differs according to the behaviour in question and a variety of other factors.”

What can we take from this? Simple: that we can’t just force ourselves to do something for x-number of days and assume that means the habit won’t budge. Instead, we need to consider other factors. Does the habit easily fit into our existing routines? Do we have a ‘why’ for doing it? Does this habit actually matter to us? Do we have the support we need to make it happen? 

It’s well worth trying out approaches other than the ‘magic number’ one, too. Habit-stacking might do the trick for you. The ’two-day rule’ could work – and this study seems to back it up. Test out techniques and remember to be gentle with yourself: you’re not a failure if you go off track, and it’s always possible to get back on it.

Main image: Unsplash

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