Fortunately or unfortunately, most of us live in W.E.I.R.D. societies. 

Western. Educated. Industrialized. Rich. Democratic. Societies. 

This is the acronym coined by Harvard University professor of evolutionary anthropology Joseph Henrich to describe the unique features of our modern societies, and one of his most astonishing claims, among many others, is that the rise of Europe and America as modern societies rests upon the Christian church’s promulgation of incest taboo during the Medieval period, and according to many, many research data as elucidated in his book The WEIRDEST People, incest is significantly more common in all non-western countries, even to this day.

So in all sense, the modern western societies and by extension western people, far from being the standard bearers of human development, are actually very abnormal when viewed ontogenetically as the co-product of cumulative cultural evolution and entwined biological evolution. 

I’m not going to summarize the entire book for you, but the main take-away is, if you are a westerner, you are actually weird. You are very, very abnormal. Your morality is abnormal. Your way of life is abnormal. Your way of thinking is abnormal. Your psychology is abnormal. Even the physiological structure of your brain is abnormal. Most humans do not have some bridge inside your brain that’s either connected or disconnected and it only appears in western people. I don’t remember exactly. You can read his book to look it up. 

Any who …  so if you are a westerner, you are a freak of nature, and you are totally different from a non-westerner in just about every aspect of your mental states.

So it is no surprise then that westerners seem to have such aversion toward incest, when incest naturally occurs in nature, and almost all non-westerners practice incest. Incest marriage is very common in the Middle East, Asia, Africa, Latin America, the Indian subcontinent, and just about every other non-western society where humans were allowed to live freely according to their own values and their own nature. 

It is only in western societies that incest is banned and frowned upon, where incest is a taboo, where people are told from a young age that it is wrong to engage in incest. 

Animals engage in incest all the time. I used to raise rabbits because I have a cousin who worked in a bio-lab where they used rabbits for experiments, and sometimes they have spare ones to keep when the rabbits survive the experiments and so we take them home as either pets or food. Well, I soon discovered, almost all the rabbits are inbred. Fathers with daughters. Mothers with sons. Sisters and brothers. You can’t tell them apart, and they are all locked in a cage together, and they engage in all kinds of sex. Same thing with cats, dogs, and many other mammals. And, as you like it (or not), many non-western humans do too. 

I’m not advocating for or against incest. I’m just pointing it out, as John Henrich and many other evolutionary anthropologists discovered in their research. That if you are against incest, you are probably a prudish westerner who, whether you realize it or not, are basing your morality and jurisprudence upon the canonical teachings of some medieval Christian churches from over 1000 years ago. 

Further reading:

The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous by Joseph Henrich