Here’s a chance to discover more about the history of race in America and about the confusions that have shaped that history. Race, as we should know, is biological, and we humans all share a common racial heritage. Culture, associated with such things as regions, languages, religions, and social customs, is not race. Unfortunately, subtle and complex crossovers between the two take place, and one product of that is racism, a burden still very much with us. Ms. Graves, using interviews, videos, and other tools to capture how cultural ideas can shape perceptions of alleged differences between “races,” offers us a chance to understand why it still persists. There’s always the hope that frank talk about the roots of racism might help us build a more inclusive society. Let’s have some.