From technology to business, two (or more) heads often prove to be better than one—but only if those heads are cognitively diverse. Top-performing companies, universities, and innovation centers are increasingly finding ways to encourage a greater exchange of ideas among their staff. Scientific journals continue to see the number of authors per paper rise, while both Nobel Prizes and patents are frequently granted to teams. The need for group problem solving has never been more critical. So what’s driving the demand?