A lot of social and cognitive psychologists study why people do dumb things, like eating until we’re stuffed, but then then eating more. Or avoiding getting tested for disease because we don’t like the name of the disease. But there’s one field that really takes pride in studying the dumb things that people do. Behavioral economics. The psychologists and economists in this field are also some of the smartest researchers in the world. One example is Danny Oppenheimer. He’s a cognitive psychologist who studies how people make decisions, especially ones that are comically irrational. He’s a Professor of Psychology and Marketing at UCLA. Prior to that he was a Professor of Psychology and Public Affairs at Princeton University. He’s received awards for being a top teacher, as well as the Ig Nobel Prize for Research that Makes you Laugh. He also wrote a popular book on the Science of Giving. We caught up last week to do one of his favorite hobbies, eat chocolate chip cookies. When I asked him to do the interview he warned me that the answers to this interview (like the answers he has discovered in the rest of life) would relate to chocolate chip cookies. In this week’s interview, he’ll teach you about people’s decisions, especially the ones we make that are really dumb. He’ll also teach all of us how to be a little smarter.