Uncovering the Truth Behind Habit Formation with Machine Learning Beyond the 21-Day Mark

A new study from scientists at California Institute of Technology (Caltech) has revealed that it can take up to six months to form a gym habit, and just a few weeks to form the habit of hand washing. This dispels the myth that it takes 21 days to form a habit, and highlights how habit formation speed changes depending on the behaviour in question and a range of other factors. The study, which appeared in the Proceedings of the National Academy of Sciences, is the first to use machine learning tools to study habit formation. The researchers used machine learning to analyse data sets of tens of thousands of people who were either swiping their badges to enter a gym or washing their hands during hospital shifts. The data sets were used to track over 30,000 gym-goers over four years and over 3,000 hospital workers over nearly 100 shifts. The results showed that some variable do not affect gym habit formation, while certain factors such as past behaviour was a key determinant in creating a habit. For 76% of gym-goers, the amount of time that had passed since a previous gym visit was an important predictor of whether the person would return.