It's a well-documented phenomenon, which researchers have had more opportunity to study in recent years, since the advent of the internet made adoption reunions much more common.
When a child adopted at birth is reunited in adulthood with his or her biological family, apparently sexual attraction between family members is not uncommon.
Typically, these feelings are quite unexpected and unwelcome, and can be upsetting and disturbing to everyone involved.
Genetic sexual attraction - Wikipedia, the free encyclopedia
Damn thats freakadelic, I assumed theyd have some sort of pheremonal olfactory response produced by similars or something that would prevent them from being attracted to one another. Weird.
We are all descended from tribal, indigenous people, and a tribe is nothing but a big extended clan or family, with only an occasional infusion of fresh blood, perhaps, when an outsider is brought in.
Last edited by 1069; 07-10-10 at 01:23 AM.
Tribes, however are rarely isolated from one another and 'trade' would be spouses and arrange marriages. Also a tribe could not survive genetically with rampant incest in isolation. What is the rate of birth defect from incestuous reproduction? Would the offspring even survive?
Maybe I'm conservative (small "c") about it or anally retentive but I just find the subject totally distasteful and I'd be against incest becoming acceptable behaviour.
The risk of birth defects from an incestuous union is not terribly high; less, as has been mentioned, than for a woman over 40 giving birth via a non-incestuous union.
The royal families of Europe, throughout the classical and medieval eras and well into the renaissance era, were almost exclusively comprised of products of incest. In an effort to keep rulership of the entire Western World in the hands of the same few families, first cousins, uncles and nieces, and aunts and nephews were betrothed and married to one another with regularity. Such marriages were the norm for the time, rather than the exception to the rule.
Did they have a lot of birth defects, even after a dozen generations of such inbreeding?
Well, they weren't a terribly healthy bunch in general, not by today's standards... but few people were, at the time. There was no modern medicine; most of them- like all people of their time- died of illnesses that would be preventable or easily curable today.
The only possibly-incest-related effect that I can think of was a high incidence of hemophilia among the Royal Families; it was so common, in fact, that it was known at the time as "Kings' Disease".
I know there's a genetic component to hemophilia; I'm not sure if incest causes it to occur in a family at higher rates.
You can also look at the Ashkenazi Jews, who until this century didn't interbreed (at least not by choice) with gentiles, to the point that 40% of today's Ashkenazi Jews have recently been traced back to just four common female ancestors.
Yes, they do have a higher rate of certain genetic disorders; also a higher rate of certain cancer-causing genes. Nothing earth-shattering, though. They also have a (slightly) higher median IQ than any other ethnic group on earth, so maybe thousands of years of reproductive isolationism made them smarter. Who knows?
Maybe they, as a culture, simply evolved or adapted to be smarter, because of their particular historical experiences.
It would be interesting if someone would do a similar study on the Hmong, who have been even more genetically isolated than the Jews, until even more recently. In fact, over 90% of the Hmong in the US derive from ten major clans, or families, and share the same surnames.
However, within the Hmong culture, there are strict cultural taboos/ prohibitions against marrying within one's clan.
That doesn't mean one can't marry somebody just one generation removed from one's own clan, however, and I'm sure they frequently do.
Last edited by 1069; 07-10-10 at 02:16 AM.
I'm also well aware of a potential self identified charge of hypocrisy when I read 1069 speaking of "historical/anthropological perspective, or even a Biblical perspectives" - if you believe in the bible, we're all related through from two original ancestors (Adam and Eve) and if you go with evolution, we may all be related through a very small subset of ancestors.
Biblically - we're all involved in some form of incest anyway. Genetically, we may not all have the exact same two original ancestors but there's a very high chance of a common set of ancestors (no way of knowing how many or few there were)
My head's spinning.
"To waste, to destroy, our natural resources, to skin and exhaust the land instead of using it so as to increase its usefulness, will result in undermining in the days of our children the very prosperity which we ought by rights to hand down to them."~ Theodore Roosevelt (Message to Congress, Dec. 3, 1907)