Why Race Isn't as 'Black' and 'White' as We Think - New York Times:

The test results underscore what anthropologists
have said for eons: racial distinctions as applied in this country are
social categories and not scientific concepts. In addition, those
categories draw hard, sharp distinctions among groups of people who are
more alike than they are different. The ultimate point is that none of
us really know who we are, ancestrally speaking. All we ever really
know is what our parents and grandparents have told us.

Interesting that the Berkeley Public Library chose The House on Mango Street for "Berkeley Reads Together".