>>715595147
>sustained, repeated multigenerational incest mass produces retards
Actually that's the opposite of the truth.
https://en.wikipedia.org/wiki/Genetic_purging
Because of natural selection removing harmful alleles, only the first couple of generations produces retard offspring. After that, you then have a group that is genetically homogeneous enough that they can fuck their sisters all they want with zero consequences. Isn't science neat?