Hidden Brain Liar, Liar, Liar We all lie. But what separates the average person from the infamous cheaters we see on the news? Dan Ariely says we like to think it's character — but in his research he's found it's more often opportunity. Dan Ariely is a professor at Duke University and the author of the book, The Honest Truth About Dishonesty: How We Lie to Everyone — Especially Ourselves. We spoke to him in March 2017.