Hereditary means a lot. I see it in all four.
My kids spend time with with other white identified blacks occasionally. American blacks don’t enter in the picture much. One kid had the southern college attended practically fore her into their black social group. She lasted about ten minutes. They didn’t fit.
Otoh she ended up engaged to her white roommate’s wealthy neighbor at the end of her time there.
That was almost 15 years ago. The world is more twisted today
I'm not an adoptive parent. I gave birth to my children, who happen to be "mixed." Whether my kids referred to themselves as black or mixed was fine with me. One even preferred the term mulatto. But, they've never called themselves white, and neither have I, because that's not what they are.
Growing up, they had friends of all backgrounds, and they all got along well. They joked around with each other without anyone becoming offended. Whenever race was a topic in the news, my kids would roll their eyes and say they were sick of hearing about race. Then, college happened, with mostly white leftist professors and "woke" white friends. Then 2020 happened. My now-grown kids have mostly white friends who are woker than woke.
My kids once had some black friends. You know what those black friends spend time talking about, even today? Their love for Jesus. I sooooo wish my kids were closer with those friends, who were raised by married black parents.