When do fact-checks work? And when do they backfire and cause someone to dig in? Yamil Velez, a political scientist at Columbia University, set up an experiment using chatbots and found that people can change their mind, even on deeply held beliefs. Except under one condition: when the chatbot is rude.Get more from your favorite Atlantic voices when you subscribe. You’ll enjoy unlimited access to Pulitzer-winning journalism, from clear-eyed analysis and insight on breaking news to fascinating explorations of our world. Subscribe today at TheAtlantic.com/podsub. Learn more about your ad choices. Visit megaphone.fm/adchoices