Are you completely free of any preconceived notions of the characteristics of groups of people, even groups you belong to? Few of us are.
Maybe we all want a better country, but our ideas for building one differ greatly. And our ability to work as one people is hindered by our notions of who the "other people" are.
Max Klau, a developmental psychologist, explores these concepts in his book Race and Social Change: A Quest, A Study, A Call to Action. The book centers on a "separation" exercise used at leadership conferences for young people.