Everyone has heard that it takes 21 days to make a habit. This is the true story of where that number came from — and of what scientists found when they actually measured it.
Ten words and phrases in four activities. Say your answer out loud before you reveal it.
Three words: a routine · to stick to · a myth. Say the right one, then reveal.
Read each part. Then answer the quick questions from memory before you check. Then discuss the question.
In 1960, an American plastic surgeon called Maxwell Maltz published a self-help book, Psycho-Cybernetics. In the preface, Maltz wrote about something he had noticed in his patients: "Following plastic surgery it takes about 21 days for the average patient to get used to his new face."
He gave other examples. After people lose an arm or a leg, the strange feeling that it is still there lasts, he said, about 21 days. People must live in a new house for about three weeks before it begins to "seem like home". His conclusion: it requires "a minimum of about 21 days" for an old picture in our mind to disappear and a new one to form.
Maltz was writing about getting used to a change — a new face, a new home. He was not describing a scientific study of habits. But over the years, his words were repeated, simplified and repeated again. The word "minimum" disappeared. The new face disappeared. What was left was a neat, hopeful rule that you can still find in countless articles and apps today: it takes 21 days to form a habit.
Decades later, psychologists at University College London tracked the famous number back to Maltz's book. Getting used to something and forming a habit, they pointed out, are not the same thing. So how long does it really take?
1. What was Maltz really writing about when he mentioned 21 days?
2. How did his idea change over the years?
1. Getting used to a change, such as a new face after plastic surgery or a new house. It was based on his observations, not on a study of habits.
2. People repeated and simplified it. "A minimum of about 21 days" for a mental image to change became "21 days to form a habit".
In a study published in 2010, Phillippa Lally and her colleagues at University College London decided to measure habit formation properly. They recruited 96 volunteers. Each person chose one new healthy behaviour — for example, drinking a glass of water — and connected it to a daily cue, such as "after breakfast". Then they did it every day for 84 days.
Every day, the volunteers also answered questions about how automatic the behaviour felt. At first, each repetition made a big difference. Then the progress became slower and slower, until the line on the graph became flat. The researchers took that flat point as the moment when the habit had formed.
The average time was 66 days — more than three times longer than the famous 21. If you start a New Year's resolution on 1 January, that takes you to early March. But the most interesting result was the range. For one person, the habit formed in just 18 days. For another, it hadn't formed by the end of the study, and the researchers calculated that it would take about 254 days.
Simple behaviours, like drinking water, became automatic faster than harder ones, like doing fifty sit-ups. Psychologists from the same UCL department summed it up simply: forget the magic number. If you keep doing the same thing in the same situation, a habit will form — but it will probably take longer than you think.
1. What did each volunteer do in the UCL study?
2. What were the average and the range?
1. They chose one healthy behaviour, linked it to a daily cue (for example, after breakfast), did it every day for 84 days and reported how automatic it felt.
2. The average was 66 days. The range was from 18 days to an estimated 254 days.
In May 1971, two American congressmen came back from Vietnam with shocking news: heroin use among American soldiers there was widespread. The US Department of Defense quickly set up urine tests for soldiers leaving Vietnam. Then a researcher from Washington University in St Louis, Lee Robins, was asked to find out what happened to the men after they returned home.
Robins's team interviewed about 900 soldiers who had come home in September 1971. The numbers were frightening. Heroin in Vietnam was cheap and very strong. 85 percent of the men said they had been offered it, 35 percent had tried it, and 19 percent — almost one in five — had become addicted.
Heroin addiction was seen as one of the hardest habits in the world to break. But when Robins followed the men for three years after they came home, only 12 percent of those who had been addicted in Vietnam had relapsed into addiction at any time. The researchers admitted that the results were very different from what they had expected, and from what doctors saw in addicts who came to them for treatment.
Robins discussed one obvious explanation: back home, almost everything had changed. Heroin was much harder to get, and the men were far from the war, in different places, with different people and different routines. Robins was careful — the war was a very unusual situation. But many psychologists who study habits today see her study as a powerful lesson. A habit is not only inside us. It is tied to the places, people and cues around us. Change the situation, and the habit can lose much of its power.
1. What percentage of the soldiers became addicted in Vietnam — and what percentage of them relapsed after coming home?
2. What is the explanation that many habit researchers take from this study?
1. 19% became addicted. Only 12% of those relapsed into addiction in the three years after their return.
2. Habits are tied to situations and cues. When the men's whole environment changed, the habit lost much of its power.
Maltz wrote that patients need time to get used to a new face. We all used to do things we don't do now. These four structures look similar, but they mean very different things.
Use used to, would, be used to or get used to and the verb in brackets.
1. Before the study, people (believe) that habits took 21 days.
2. Maltz said patients needed about three weeks to (their new face).
3. When I was a student, I (stay up) until 3 a.m. every Friday.
4. After ten years in London, she (drive) on the left. It feels normal now.
1. used to believe 2. get used to their new face 3. used to stay up / would stay up 4. is used to driving
3: both are possible because it is a repeated action. 4: be used to + -ing because it is normal for her now.
Rewrite each sentence using the structure in brackets.
1. When the soldiers were in Vietnam, heroin was cheap. It isn't true for them now. (used to)
2. At first the new routine felt strange, but now it feels normal. (get used to — present perfect)
3. It is completely normal for me to check my phone first thing in the morning. (be used to)
1. Heroin used to be cheap for the soldiers when they were in Vietnam.
2. I have got used to the new routine. / I've gotten used to the new routine (US).
3. I'm used to checking my phone first thing in the morning.
Check: used to + verb for the past; be / get used to + noun or -ing for familiarity.
You'll use it again in the Speak tab — Task C is about a habit you used to have and one you are getting used to.
The studies in this story are real, and the numbers come from the researchers who did them. Together, they turn the usual advice about habits upside down.
Speak against the clock — and use the four structures where they fit: used to · would · be used to · get used to.
Retell the story in your own words. Use these steps: Maltz and the new faces → "a minimum of about 21 days" → how the rule changed → the UCL volunteers and their daily cue → 66 days on average → 18 to 254 → Vietnam, 1971 → 19% addicted → only 12% relapsed → the changed situation.
Use at least three of the four structures and five key words (automatic, cue, relapse, routine, stick to, myth, resolution, range, old habits die hard, creature of habit).
First argue FOR: think about discipline, sticking to a plan, and people who changed their lives by deciding to. Then argue AGAINST: think about the Vietnam soldiers, cues and situations, and the diary studies. Finally, say what you really think — and what you would tell a friend who wants to change a habit.
Talk about three habits. One you used to have but don't any more — how did it stop? One from your childhood that your family would do regularly. And one you are getting used to right now — at work or at home. For each one, name the cue: when, where or with whom does it happen?
Or choose one of these: