That’s utter nonsense. Where did you get that drivel from??????
On average american blacks are about 20–25% white, but that’s an average – the range varies greatly ( and is obvious ).
Crossbreeding was illegal for long periods of history. And was largely a frontier (sparse population) phenomenon. Just like today, it’s people who can ‘marry up’ that cross breed.
Most germanic (and anglo) americans did not even mate cross RELIGIOUS lines until the 1950’s.
nonsense. who pays people to ask these questions?