Is it true that it takes three weeks to form a habit? The answer is yes, and no. It all depends on what habit you’re trying to change and how you go about doing it.
As researcher Phillippa Lally has found, habits can become automatic – but it takes time. To investigate how people form habits, she asked 96 volunteers to choose a new eating, drinking or other behaviour to carry out every day in the same context (such as just before breakfast).
Each day, the volunteers recorded whether they had carried it out, and 82 provided enough data to be included in her analysis. Lally found that the length of time it took participants before their habit became automatic ranged from 18 to 254 days, with an average of 66 days.
New habits take time
Thus, the time needed to form a habit, so that it really is habitual, is variable and can take a long time indeed. Furthermore, only about 40 per cent of people are successful in changing a habit on their first attempt. In fact, 17 per cent need to try six or more times before they are successful.
Skipping a day here and there does not seem to affect the habit-forming process. The habit is easier to develop, however, when done consistently — at a regular time or always in a particular place.
New habits at first take mental effort
In another study, Phillippa Lally analysed how 10 participants who were enrolled in a weight-loss programme changed their behaviour. She found that by developing habits that became automatic, the participants could maintain their eating behaviour more easily.
At first, the behaviour change took mental effort, but the more automatic the habit became, the less effort that was required. Interestingly, habits were easier to form when participants were at work. Their new routines would often get interrupted on weekends and holidays, but would be re-established when they returned to work.
As Lally summarised her findings: “Performing an action for the first time requires planning … and attention. As behaviours are repeated in consistent settings, they then begin to proceed more efficiently and with less thought as control of the behaviour transfers to cues in the environment that activate an automatic response: a habit.”
And the message is …
The take-away message from this research is that it can be a long time before a habit becomes automatic. What works best is to associate the new habit with an existing part of your daily schedule, so that the new habit follows on automatically from something you already do automatically.
For example, after I started having lower back twinges from sitting too long at the computer, the doctor told me I had to do three basic stretching exercises every day. Now every morning I get up, go to the bathroom, brush my teeth, lay out my mat and do the three exercises. It’s automatic: it’s just what I do; it takes three minutes; I don’t think about it. It’s so much a part of my routine that even if I have to get up very early to catch a plane, I still do it.
Lally, P. et al. (2010) How are havits formed: Modelling habit formation in the real world. European Journal of Social Psychology 40(6): 998-1009.
Lally, P., Wardle, J. & Gardner, B. (2011). Experiences of habit formation: A qualitative study. Psychology, Health & Medicine 16(4): 484-489.