That is such an odd statement, or maybe Florida is an outlier? On my block there is a mix of people, I went to schools that were forcefully integrated, the friend groups of my children are diverse. I grew up with friends who were a mix too. There were certainly cliques and self-segregating but not everyone, and now it's even less frequent.

My ex, who came down here from Michigan, said that he went to "the white school" up north, that in his city the schools ended up segregated because they were neighborhood schools and the neighborhoods were segregated. So even in his high school he said there were 2 black kids and a few Indian and 99.5 % white kids. He was so uncomfortable down here because we are all mixed and he ended up so racist.

I haven't lived up north but my experience with the northerners who move down here supports this, they all come from more homogeneous backgrounds than those of us who grew up here. They all think they aren't racist until they live in this more heterogenous environment.