David Logan talks about the five kinds of tribes that humans naturally form -- in schools, workplaces, even the driver's license bureau. By understanding our shared tribal tendencies, we can help lead each other to become better individuals.

Harvard Law professor Ronald Sullivan fights to free wrongfully convicted people from jail -- in fact, he has freed some 6,000 innocent people over the course of his career. He shares heartbreaking stories of how (and why) people end up being put in jail for something they didn't do, and the consequences in their lives and the lives of others. W...