Breaking bad habits often feels like a test of willpower. We tell ourselves we’ll stop scrolling, eat better, or exercise more — and then fall right back into the same routines. So why is lasting change so hard? As part of our spring cleaning series, we’re revisiting a powerful episode from The Happiness Lab archives that reveals a surprising truth about behavior change: it’s not about willpower at all. Dr. Laurie Santos sits down with psychologist Wendy Wood to explore what the science of habits really says about why we get stuck — and how we can finally change. Along the way, we hear the remarkable story of American soldiers in Vietnam who abruptly overcame heroin addiction after returning home, offering a powerful clue about how habits really work. If you’re looking to break a bad habit or build a better one, this episode shows how small changes to your environment can make lasting change feel almost automatic. Experts Mentioned: Wendy Wood, Provost Professor of Psychology and Business, University of Southern California. Dr. Richard Ratner, Clinical Professor of Psychiatry and Behavioral Health, George Washington School of Medicine and Health Sciences Resources Mentioned: Good Habits, Bad Habits: The Science of Making Positive Changes That Stick, by Wendy Wood (2019) “ How Do People Adhere to Goals When Willpower Is Low? The Profits (and Pitfalls) of Strong Habits,” by David T. Neal, Wendy Wood, and Aimee Drolet ( Journal of Personality and Social Psychology, 2013) “ The Pull of the Past: When Do Habits Persist Despite Conflict with Motives?,” by David T. Neal, Wendy Wood, Mengju Wu, and David Kurlander ( Personality and Social Psychology Bulletin, 2011) “ Ironic Processes of Mental Control,” by Daniel M. Wegner ( Psychological Review, 1994) “ How Permanent Was Vietnam Drug Addiction?,” by Lee N. Robins, Darlene H. Davis, and David N. Nurco ( American Journal of Public Health, 1974) CBS News Lottery Draft 1969 (Archival Footage) "G.I. Heroin Addiction Epidemic in Vietnam" ( The New York Times, 1971) G.I.