With examples of partisanship and tribalism seemingly all around us, it's easy to imagine that the tendency to segregate ourselves into rival groups is an unavoidable part of human nature. But Associate Professor of Psychology and Neuroscience professor Jay Van Bavel, director of NYU's Social Identity and Morality lab and the co-author of a new book, The Power of Us: Harnessing Our Shared Identities to Improve Performance, Increase Cooperation, and Promote Social Harmony, says it's not that simple. His research shows that group identity—the same thing that can turn us against each other—can also help us embrace what we have in common and work more effectively on teams.