In Europe, where I've also lived, it struck me as absurd (being an American) that so much stock is placed in ethnic DNA.

The prejudices on either continent are different. People of learning find all forms of racism repugnant, so that any mention of the genetic inferiority of African descendants or Native/Aborigines, etc., would be immediately countered.

Yet, even in polite and learned company in Europe, I find an incredible ease in discussing ethnic differences within Europe. I've always felt uneasy with that ease. It is very common. In the USA, you rarely hear racial insults on the street, but I heard ethnic insults all over Europe. In newspaper columns, for instance, I've often heard the distinction between Ancient Greeks and contemporary ones with columnists pointing out that the Classical Greek bloodline has been so mongrelized that we now have a lesser strain. I shake my head in amusement when I read such things.

I'm not trying to downplay American racism since I think its unspoken coerciveness is still easily the more virulent when compared to Euro prejudices.