Originally Posted by
Chomag7
In many cases incest is also inbreeding. Inbreeding leads to a higher proportion of congenital birth defects through an increase in the frequency of homozygotes.[49] The effects of this can diverge - recessive genes that produce birth defects could become more frequent, resulting in a higher rate potential of these defects while genes that do not code for birth defects can become increased within a population.
It's not some religious crap and it's certainly not just some perversion. It's biology: there is a high chance for recesive genes aka the bad shit genes, to combine and the result to be some retarded/malformed child.