The rush to make AI chatbots more friendly has a troubling downside, researchers say. The warm personas make them prone to mistakes and sympathetic to crackpot beliefs.Chatbots trained to respond more warmly gave poorer answers, worse health advice and even supported conspiracy theories by casting doubt on events such as the Apollo moon landings and the fate of Adolf Hitler.Researchers at Oxford University discovered the trade-off during tests on chatbots that had been tweaked to make them sound...