I've always wondered about this. Why is black the default race when someone is biracial? It's disturbing because it reminds me of the Nazi policy that labeled people as Jewish if they had any Jewish ancestry, even though they had never been brought up in the culture and might even be practicing Christians. Again and again I find our society's obsession with labeling people to be divisive and destructive. Maybe if aliens from outer space arrived we'd finally begin to understand the benefit of our shared humanity.