Creating habits: how long does it take to form a habit?

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A popular misconception which persists since the 1960s is that it takes about 21 days to change an existing habit or adopt a new habit. This magic number is used everywhere from advice columns to self-help books about creating habits. However, this is a myth. Where does it come from, and how long does it actually take?

“We are what we repeatedly do. Excellence, then, is not an act, but a habit.” — Will Durrant. (this quote is often misattributed to Aristotle)

The origins of the magic number of habit creation

Dr. Maxwell Maltz (1899 – 1975) was an American plastic surgeon. As part of his work with patients, he became interested in systems and ideas to improve their self-image. Maltz noticed that when he performed an operation, it would take about 21 days for the patient to get used to the result. He also noticed that it took himself about 21 days to adjust to new routines.

In his book Psycho-Cybernetic published in 1960, Maltz wrote: “These, and many other commonly observed phenomena, tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to gel.”

With more than 30 million copies sold, the book spread the idea that 21 days was a magic number. A contextual observation quickly became a popular myth, and people forgot two important details:

  • Dr. Maxwell Maltz’s work mostly focused on self-image, not on habit formation.
  • He wrote: “a minimum of about 21 days” — implying that it may take more than 21 days to adjust one’s self-image.

But simple ideas spread fast. 21 days, or about three weeks, has a nice ring to it: it’s short enough to feel motivational, and long enough to sound realistic. Self-help authors and coaches started using it for everything from eating better to building a productivity habit or taking up running.

Taking a step back, it’s easy to realise how flawed using such a magic number is. The idea of one universal number feels incongruous when considering the diversity of goals and personal contexts people experience when trying to form new habits.

How long it actually take to adopt a new habit

“Could the young but realize how soon they will become mere walking bundles of habits, they would give more heed to their conduct while in the plastic state,” wrote William James in his little-known essay Habits. Lucky for us, neuroplasticity shows the adult brain is not hard-wired with fixed neuronal circuits, and we can keep on creating habits as long as we cultivate a growth mindset.

Dr. Phillippa Lally is a behavioural scientist and health psychologist. During her PhD and fellowship at University College London, her work focused on habit formation and weight control. In an experimental study, her team investigated the process of habit formation in everyday life.

They enrolled 96 participants and asked them to choose an eating, drinking or other simple activity to carry out daily at the same time for 12 weeks. Each day, the participants were tasked to complete a form to record whether they carried out the activity. The goal of the researchers was to understand how long it would take for participants to build a consistent habit.

The results were very far from a fixed, universal number. In fact, the number of days it took to form a new habit ranged from 18 to 254 days. On average, it took about two months (66 days) for participants to form the habit they chose at the beginning of the experiment.

This research suggests that it can take anywhere between 3 weeks and 8 months to form a new habit. And people will need on average 2 months to build a new behaviour into their lives.

Creating habits: how long it actually takes to form a new habit

These numbers feel more natural: of course it’s not going to take the same time to build the habit of drinking a glass of water every morning, compared to building a meditation habit or a writing habit.

Embracing longer timelines

While it may be disappointing to learn that it will probably take longer — and maybe much longer — than 21 days to form a new habit, there is beauty in embracing the longer timelines.

  • Scale down your goals, scale up your ambition. Research suggests that fewer goals is better. Life is not a checklist; embracing longer timelines can be a way to help you choose fewer, more ambitious goals.
  • Focus on the journey. Forming new habits is a process. As with all processes, it’s never perfect. You will sometimes fail, and that’s alright. It’s all about jumping back on the bandwagon. Longer timelines mean you can learn to overcome your fear of failure and to fail like a scientist.
  • Learn how to learn. Forming new habits is an adventure of self-discovery. Metacognitive skills take time to develop. There is no need to rush it; it may even be detrimental. Take the opportunity to study what helps you form new habits and what may be hindering your habit creation.

When it comes to habit creation, speed is not a measure of performance. Take your time, embrace the process, and make small, incremental improvements along the way. Everything you learn about yourself while forming a new habit can be transferred to the next habit you try to adopt.

Useful tools for creating habits

In order to make the process of creating habits easier, a few tools can be used. They won’t do the work for you, but they can help highlight bottlenecks so you can adjust the process.

First, a habit tracker is a powerful metacognition tool that will encourage you to reflect on your progress. It doesn’t need to be fancy: you can use a habit tracking app, a daily log as part of your journal, or include it in your weekly review. You can even use a simple spreadsheet. As with all tools, the key is to make it easy enough so it doesn’t become an additional hassle.

Another way to make it easier to form a new habit is to find a support group or a buddy. Want to start running every week? Join a weekly running group where you share screenshots of your runs. Want to start eating healthier? Ask a friend if they’d like to commit to healthy meals together and share your best recipes with each other.

Finally, learning in public can be a great way to commit to a new habit. Initiatives such as 100 Days of Code or Daily UI are popular because they encourage people to keep on showing up everyday for long enough.

Whatever tools you decide to use, remember: creating habits takes time. Embrace the journey. Fail like a scientist. Learn how to learn.