You quoted me but I actually didn't say anything about race or genetics. My original response was to the parent which was claiming that "tribalism is avoidable" and I was arguing against that saying that humans will always self-segregate into tribes so it's unavoidable.

Examples:

- I had a friendship which originally started over shared nostalgia for a cantonese children show

- I was excluded from a group because I didn't know enough american pop culture references to get their jokes

- I stopped eating dinner with another group because I felt awkward being the only one not praying before the meal

- In another group, we only ever talked about programming puzzles and non-programmer friends (such as their girlfriends) learned quickly to leave us alone

All of these groups came together and/or left each other due to unwritten emergent social dynamics. You can never stop these clusters from forming. As long as you have groups/tribes, there will be people excluded based on the that tribe's values. Is that really so bad?