Humans have built hugely complex societies and technologies, but most of us don’t even know how a pen or a toilet works. The key to our intelligence lies in the people and things around us. The human mind is both brilliant and pathetic. And yet each of us is error prone, sometimes irrational, and often ignorant. But our collaborative minds also enable us to do amazing things. About the Author Steven Sloman is a professor of cognitive, linguistic, and psychological sciences at Brown University. He is the editor in chief of the journal Cognition. He lives with his wife in Providence, Rhode Island. His two children have flown the coop.Philip Fernbach is a cognitive scientist and professor of marketing at the University of Colorado’s Leeds School of Business. He lives in Boulder, Colorado, with his wife and two children.