One of Yale University’s most popular courses isn’t about history, economics, or English lit. It’s about how to feel happy. Now the school is offering a free online course about the psychology of happiness designed specifically for high schoolers. The six-week course, the Science of Well-Being for Teens, offers TikTok-length videos on topics such as misconceptions about happiness, finding social connections, and tuning out your inner critic. The goal isn’t to get rid of negative emotions entirely but to figure out better ways to react to them, says instructor Laurie Santos. The videos are based on the college-level psychology of happiness class Santos teaches at Yale; when it launched in 2018, it became the university’s largest class, with more than 1,200 students. Many young people are struggling with their mental health, experts say, especially after the Covid-19 pandemic. “We all are working on feeling happier and working on helping the people we care about feel happier,” Santos says. “We don’t always know the best ways to do it, and so arming people with these evidence-based strategies can really be helpful.”