| Kyzumi said: It is not due to "genetic" reasons since it has was forbidden in most places much before people even knew what "genes" were. I also doubt they could see a pattern between some birth defects and siblins relations. |
Suppose there was a population with no taboo against incest. Suppose also there was a gene in a tiny proportion of the population for aversion to incest. The gene would be favoured by natural selection and spread throughout the population because those who possessed it would on average have more healthy offspring.
So I would argue (especially as the incest taboo is universal) that it is genetic reasons. No concious decision making required, just normal evolutionary processes.










