A sister-in-law who is South African shared that American culture has so influenced that country that some of her classmates in high school referred to themselves at African American because they believed it to be more politically correct than saying black.
I suspect someone played a practical joke on your sister-in-law. As an example of how American culture has not influenced South Africa: "Coloured"[1] is legitimate racial category in South Africa which is can be freely mentioned in polite company and even on government forms. Incidentally, it refers to a non-black demography (and most black people do call themselves black). I believe the term "Colored" has fallen out of favor in American culture, and arguably constitutes fighting words.
FWIW, I believe the term ‘Coloured’ in the South African context refers to a specific ethnic group that came about by mixing between white and native Africans. Which is different than the (now dated) term ‘Colored’ in the American context, which referred simply to people with African ancestry. So, if my understanding is correct, a South African Coloured is different from a Black South African. But in the US, both ‘black’ and ‘colored’ refer to the same people.
