I Beg to differ. You just posted the definition of cultured, which in reality is all about education. Nowhere does it state that you must be an accepted part a certain culture to be cultured in it. I wouldn't even call some Americans cultured in the United States, yet they live here.
So...by definition they have to be cultured in the United States because they ARE the culture, they are the demographic.
Look:
• the customs, arts, social institutions, and achievements of a particular nation, people, or other social group
That is waht I'm talking about, the culture is the whole, not a subgroup, an unintelligent person can be cultured in their own culture because they ARE the culture.
A) Customs: Sould food, Sunday football, et cetera
B) Arts: Bluegrass Music
C) Achievements of a Particular Nation, People, or Other Social Group: Voting, Black politics, Harley Davidson owners/riders, NASCAR fans, drivers.
Now those are all part of the American Culture, Andrew, and I bet you hundreds of thousands of people know more about all of those than you do, but, as always you would not consider them "cultured" in their own culture.