> Humans are tribal though, as in maximum 200 people. Everyone else is an "outsider". Everything above that number is the treated the same, regardless of ethnicity, as a foreigner.

That's a cute idea, but it doesn't take more than a few minutes of reading the news, or a few hours of first hand observation, to find plenty of examples where people very much do not treat everyone outside their ≤ 200 person tribe “the same, regardless of ethnicity”.

> You can't seriously suggest millions of people think the same because of their genetic markup.

The grandparent post refers to culture and ethnicity (the latter being an identity of shared culture) not genetics. Culture is essentially shared ritual, values, and historical narrative, and, yes, shared culture is significantly about thinking the same way.

>>> That's a cute idea, but it doesn't take more than a few minutes of reading the news, or a few hours of first hand observation, to find plenty of examples where people very much do not treat everyone outside their ≤ 200 person tribe “the same, regardless of ethnicity

Um... Yeah, exactly. What's your point? It was a point of gossip to marry someone from the next village. So yeah, strangers were bad.

>>> The grandparent post refers to culture and ethnicity (the latter being an identity of shared culture) not genetics.

So... Like what is the relationship between a homogenous culture and crime rate again?!

You actually think people wouldn't kill themselves because they are from the same culture?

Ethnicity is not genetic. It's a social construct that refers to groups based on shared culture / language / nationality. The genetic similarity comes from reproduction among the population as a whole over a period of time. It's a consequence, not the cause.