Most of us would agree that there’s a clear—and even obvious—connection between the things we believe and the way we behave. But what if our actions are driven not by our conscious values and beliefs but by hidden motivations we’re not even aware of? The “hidden brain” is Shankar Vedantam’s shorthand for a host of brain functions, emotional responses, and cognitive processes that happen outside our conscious awareness but have a decisive effect on how we behave. The hidden brain has its finger on the scale when we make all our most complex and important decisions: It decides whom we fall in love with, whether we should convict someone of murder, and which way to run when someone yells “Fire!” It explains why we can become riveted by the story of a single puppy adrift on the ocean but are quickly bored by a story of genocide. The hidden brain can also be deliberately manipulated to convince people to vote against their own interests, or even become suicide terrorists. But the most...
