How long does it take to build a habit?
· Source: Lally, van Jaarsveld, Potts & Wardle, European Journal of Social Psychology, 2010
You decided to drink a glass of water first thing every morning, or stretch for five minutes before bed, or water the plants on the windowsill before they give up on you. The first week went well. In the second you forgot twice, and by the third you were wondering why it still takes effort. Weren’t habits supposed to kick in by now?
Somewhere along the way you probably picked up a number, a few weeks, after which a new routine is meant to run by itself. When it doesn’t, it’s easy to decide that you’re the problem. A team in London actually measured how long this takes, and their answer is kinder than that conclusion.
A daily action after breakfast
Lally, van Jaarsveld, Potts and Wardle asked 96 volunteers to pick one new behaviour to do every day. It could be about eating, drinking or exercise, and it had to happen in the same situation each time, for example “after breakfast”. The study ran for 12 weeks.
Every day, people noted whether they had done the action and answered a few questions about how automatic it felt: whether they did it without thinking, without having to remember. Of the 96, 82 gave enough answers to analyse, and the researchers followed their scores across the 84 days.
That question about automatic is the heart of it. A habit in this sense isn’t something you do often. It’s something you do without deciding to, because the situation reminds you before you’ve thought about it.
Fast at first, then a slow climb
For most people the scores rose in a recognisable shape. Gardner, Lally and Wardle later described it plainly: the early days brought quick gains, then the progress slowed and levelled off at a plateau.
That shape explains the frustrating second week. The early jump feels like the habit is nearly done, and then the progress slows down. Nothing has gone wrong at that point. The steep part of the curve is simply behind you, and the flat part takes longer than the steep one did.
So how many days?
There wasn’t one number. The time people needed to get close to their plateau ranged from 18 to 254 days. Lally’s team could fit the curve for 62 people, and it fitted well for 39 of them, so the range comes from a fairly small group. Several estimates reach well past the 12 weeks of the study, which means they’re estimates from each person’s curve rather than days anyone actually counted.
The average for those people came out at 66 days, as the same team summed it up for doctors in Gardner, Lally and Wardle’s 2012 paper. So a little over two months is a fair middle, with wide room on either side.
If your new routine still needs a reminder after three weeks, that’s not a sign you’ve failed. You’re on the long, flat part of the curve, which is where most people in the study were too.
Missing one day didn’t break it
One finding deserves more attention than the number of days. In the original analysis, missing a single chance to do the behaviour didn’t materially change how the habit grew. The 2012 summary put it in practical terms: after one missed day, people’s progress soon picked up again.
This matters because a missed day is where many attempts end. The streak breaks, the whole thing starts to feel pointless, and a lapse of one day turns into a lapse of a month. According to the study, a single day off costs very little. What costs more is deciding that the whole attempt is over.
The cue does half the work
Every volunteer tied their action to something that already happened each day. That design choice is the practical lesson. “Drink more water” is a wish. “A glass of water after I turn the kettle on” has a moment attached, and the moment does the reminding.
In their advice for patients, Gardner, Lally and Wardle suggest the same thing: choose one simple action, plan when and where you’ll do it, and pick a time and place that come round every day. Our own addition is to keep it small. A tiny action is easier to repeat on a bad day as well as a good one.
Starting on a day that feels new
If you’ve dropped a habit before, the date you restart can help. Dai, Milkman and Riis looked at when people turn to their goals and found they do so more often after landmarks: the start of a week, a month or a year, or a birthday.
You can use that without waiting for New Year. Monday morning or the first of the month works as a clean line between the old attempt and the new one. Just keep in mind that the landmark gets you started. It’s the repetitions in the weeks after it that do the slow work.
The watering can by the kettle
Here is an invented example. Ana’s plants have been half-dead since spring, and she wants to water them every morning. For three weeks she relies on remembering, and the plants get water on the days she happens to look at them.
On the first of the month she changes one thing. She fills the watering can in the evening and leaves it next to the kettle. Every morning the kettle goes on, and the can is right there, so she waters the windowsill while the water boils. By the second week she still notices herself doing it. By the second month she sometimes can’t remember whether she did, because it happened without a thought, and the soil is damp when she checks.
She misses a few mornings when she stays at her sister’s place. When she gets back, the can is still by the kettle, and she carries on.
A habit is the action you stop having to remember.
When a habit needs more than patience
Some habits are about health in a way that deserves more than a two-month experiment, such as how much you drink, how you eat or how you sleep. If you’ve tried to change one of these several times and it keeps slipping, a doctor can help you plan it properly. The same goes for habits that feel out of your control, or for the opposite problem: you’ve stopped looking after yourself in ways you used to manage without thinking. Losing old routines, along with low energy or low mood that lasts for weeks, is something to raise with a doctor or therapist rather than solve with willpower.
Try it tonight
- Pick one small action and tie it to something you already do every day, like boiling the kettle.
- Do it straight after that moment, and if you miss a day, simply do it the next one.
- Once a week, say how automatic it feels now, from “I have to remember” to “it just happens”.
Tell Halflight once a week how the new habit is going. It keeps those notes by date, so after a couple of months you can read back when it stopped taking effort.