[update March 20, 2016: Commenter “Swank” deserves a lot of credit for at least subconsciously inspiring me to write this post. Swank has long argued that ethnocentric behavior is misfiring of normal kinship altruism. However the term misfiring implies that ethnocentric behavior is not genetically adaptive because it was and is not arguably selected for, which I consider a non sequitor]
One of the arguments that often gets made against Ethnic Genetic Interests (EGI) is that we couldn’t have evolved to act on our EGI because through most of evolutionary history, people never saw anyone of a different race.
But it suddenly occurred to me that this argument supports EGI rather than refutes it. If humans evolved to live in small tribes where everyone looked like they do, they would have had to have evolved extremely precise kinship recognition to behave more altruistically towards their brothers than their half-brothers, to their first cousins than their second cousins etc..
A person who was more generous to his second cousin than his first cousin would have lower inclusive fitness than a person who was more generous to his first cousin than his second, because our first cousins share more of our genes than our second cousins. Thus what likely evolved was an instinctive ability to compare two people, decide who is more related to you, and prefer the more genetically similar person.
Now when humans met members of other races, this hierarchical kinship recognition simply caused them to be more altruistic to their own race than to other races and this largely explains racism. So I guess one could argue that racism per se didn’t evolve, but hierarchical kinship preferences did, and races are just extended kin, and so the recognition system works on races as long as the genetic similarity between them correlates with something humans can instinctively recognize (physical similarity).
Does this make racism genetically adaptive or was hierarchal kinship preference only adaptive when humans lived in tiny genetically homogenous groups where it distinguished between close relatives, not extremely distant relatives? Its hard to judge the genetic adaptiveness of something that may not have been tested much by natural selection, but there’s no question that if you maximize the genetic fitness of your race while minimizing the costs to your individual genetic fitness, you have increased your total genetic fitness relative to the average human.