In this lecture Ariely talks about his latest book The Upside of Irrationality where he shows the negative and positive effects of irrationality and how we can use irrational means towards our own rational objectives. He tells of experiments and examples where irrational incentives were used to help fight global warming, to motivate people to take care of their health, and to prevent people from texting while they're driving. It's one of the most fun lectures we've listened to all year.