Is tribalism destroying democracy? According to cultural psychologist Michael Morris of Columbia University, just the opposite may be the case. As he explains in his new book, Tribal, our tribal instincts can also be the source of our success--in politics, society, business, and even professional sports. Listen as Morris and EconTalk's Russ Roberts discuss real examples of how smart leaders pulled tribal levers to improve performance, solve stubborn problems, and create positive change.