How long does it take to form habits?

A paper recently published in the European Journal of Social Psychology by Lally et al. (2009) looked at the question of how long it takes to form new habits. Very little scientific research had been done on this question;  the general understanding was that it takes more or less a month, depending on the habit and whether it was designed to replace an old 'bad' habit, such as smoking. It was assumed that an easy habit to form - lets say drinking a glass of water every morning on waking - would, in comparison, take very little time to become automatic. Whilst this all made sense there was, until Lally's research, no real evidence to support it. 

What the researchers found was that on average a new habit became embedded - and therefore automatic - after 66 days, and that at 66 days it had become as much a habit as it was ever going to become. 

Although the average was 66 days, there was marked variation in how long habits took to form, anywhere from 18 days up to 254 days in the different habits examined in this study. As you'd imagine, drinking a daily glass of water became automatic very quickly but doing 50 sit-ups before breakfast required a great deal more dedication. 

What was critical to success was the daily repetition. The researchers also found that missing the odd day did not reduce the chance of forming a habit, and that some people take longer to form habits than do others.

What this study reveals then, is that if we want to develop a relatively simple habit like taking a 5 minute walk in the park, it could take us no more than a month of daily repetitions before the behaviour becomes a habit, but if we want to introduce a habit such as 'not' smoking, or doing 50 sit-ups before breakfast then it will take at least 66 days and possibly more. The crucial key to success was daily repetition.

The question of what kinds of habits we should adopt is another story. Well it's a book actually - The Real Secret.