IBM's super-computer Watson was a runaway success on Jeopardy! But it wasn't nearly as good at diagnosing cancer. This came as no surprise to Max Planck Institute psychologist Gerd Gigerenzer, who argues that when it comes to life-and-death decisions, we'll always need real, not artificial, brains. Listen as the author of How to Stay Smart in a Smart World tells EconTalk host Russ Roberts why computers aren't nearly as smart as we think. But, Gigerenzer says, human beings need to get smarter in order to avoid being manipulated by people who use AI for their own ends.