Anti-vaxxers are a good example. Despite studies repeatedly debunking the link between vaccines and autism, plenty of people still believe vaccines cause autism. Many people who know someone who has experienced side effects from a vaccine start to believe vaccines are dangerous regardless of any studies demonstrating how exceedingly rare said side effects are.
Flat Earthers are another example. While undoubtedly some of their ranks are people just trying to be contrarian, the true believers will find alternative explanations for every piece of evidence you try to show them that Earth is indeed round.
Anti-vaxxers are a good example. Despite studies repeatedly debunking the link between vaccines and autism, plenty of people still believe vaccines cause autism. Many people who know someone who has experienced side effects from a vaccine start to believe vaccines are dangerous regardless of any studies demonstrating how exceedingly rare said side effects are.
Flat Earthers are another example. While undoubtedly some of their ranks are people just trying to be contrarian, the true believers will find alternative explanations for every piece of evidence you try to show them that Earth is indeed round.