On that last bit...
Remember that Star Trek episode, [link|http://www.starfleetlibrary.com/tos/tos3/let_that_be_your_last_battlefield.htm|Let that be your last battlefield]? The one with Bele and Lokai?
Well, being able to distinguish differences between ethnic groups is something that we don't seem to be very good at. (At least I'm not.) It's sort of funny because the human brain is so very good at recognizing faces...
We have a CNA who's worked for us for nearly a couple of years. She's originally from Ethiopia. Let's call her Missy. For a while we had some additional temporary aids helping out. They were generally originally from Mali or Ghana. Their skills varied. Once Missy was telling us about some difficulty she had with one of the other aids and said under her breath, "Oh, those Africans!" :-/
I think you're right that most Americans (and most people?) would lump broadly similar looking strangers together in their minds. I think all of this helps to demonstrate the truism that discrimination must be taught. That is, kids quickly develop the concepts of Me, Family, and Others. Others gets modified over time (friends, acquaintences, enemies, etc.) and I think it's these modifications that leads to us having knee-jerk reactions to people of certain groups. There's nothing innate about us that makes us fearful of people who look "different" - it's a cultural thing.
Cheers,
Scott.
