Social scientist Arthur Brooks says you should really think twice before calling someone a liar.
"When you're talking to somebody else, you're not positioned to say that that person is a pathological liar," he says. "What you know, or what you believe, is that person is saying something is untrue — and that's what you should take on."
Brooks' new book is called Love Your Enemies: How Decent People Can Save America from the Culture of Contempt. It aims to guide people on different sides of the political divide to have constructive conversations.