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Knowledge at Wharton: What Machine Learning Reveals About Forming a Healthy Habit

From Knowledge at Wharton: Wharton experts used machine learning to help uncover the secret formula for successful healthy habit formation, and it turns out there’s no one formula. “There’s this widely spread rumor that it takes 21 days to form a habit. You may have also heard it takes 90 days to form a habit. There are popular books that tout these numbers that don’t have a sound basis in research. What we find is there is no such magic number,” said Katy Milkman, a Wharton professor of operations, information and decisions. Milkman spoke to Wharton Business Daily on SiriusXM about her recently published study. Wharton professor Angela Duckworth, who co-founded Penn’s Behavior Change for Good Initiative with Milkman, is one of six co-authors* on the piece.

The ‘Magic’ Behind a Healthy Habit

The team including Milkman and Duckworth developed a machine learning methodology to parse millions of data points tracking two behaviors that can become habitual: gym attendance and hand sanitizing. They partnered with 24 Hour Fitness to obtain years of check-in records for more than 60,000 gym members, and they worked with a technology company that tracked whether 5,200 health care providers at 30 hospitals sanitized their hands whenever they entered or exited a patient’s room. They found that it took, on average, weeks for people to get into the habit of hand sanitizing and months to start going to the gym regularly. The time element isn’t more precise because there was so much variation in the data across individuals, which Milkman said is further proof that a magic number is elusive. Listen to the full episode at Knowledge at Wharton.