What makes creative relationships work? How do two people—who may be perfectly capable and talented on their own—explode into innovation, discovery, and brilliance when working together? These may seem to be obvious questions. Collaboration yields so much of what is novel, useful, and beautiful that it’s natural to try to understand it. Yet looking at achievement through relationships is a new, and even radical, idea. For hundreds of years, science and culture have focused on the self. We talk of self-expression, self-realization. Popular culture celebrates the hero. Schools test intelligence and learning through solo exams. Biographies shape our view of history.