While looking for this info, I came across this tidbit: James Watson, who claimed blacks are intellectually inferior to whites, is 1/6 black. Wonder how he felt on finding that out, especially since he's the guy who said, "I didn't win a Nobel prize. I won the [meaning most important ever] Nobel prize."

I know a woman who I think had negative feelings about blacks, who learned, as an adult, that her father was black. She'd always thought he was Hispanic. She was a little upset by it, but mostly thought it was a funny story to tell people.

One original publication is in the Feb. 8 2008 Nature Genetics. I don't have it. Articles citing it here. None of the titles mention race.