This is pretty easily refuted by the fact that something can exist in the subconscious / doesn't have to be articulated all the time.
Huh, interesting seeing you argue that subconscious biases are a major force in society. They might have a bearing, (I'm sure you've read the study "Are Emily and Greg More Employable than Lakisha and Jamal"), but is it reasonable to say that they dictate a majority of our social interaction?
people have social connections passed down generationally
Right, so ideally people stick within their own "nation", or "tribe", or if you will, "clan". See, Scotland used to be divided into clans; they'd fight each other, only breed amongst themselves, massacre each other, but eventually we learnt how to look beyond the world in such a simple manner. Today, most Scots could probably tell you what clan they're a part of, but they don't give a fuck, when it comes to interacting with people. As the world becomes more globalised, why can't the same thing happen, on a global scale? if your logic was applied throughout history, a MacDonald and a Campbell would've always ideally self-segregated to the point where people only interact with those who they share social connections from generations that aren't their own.