February 20, 2005

Is there a "gay gene"

There's a VERY interesting interview with an expert in population biology, Gregory Cochran, here on the subject of the so-called "gay gene" -- a gene nobody has been able to find. I didn't realize that the rate of discordance among indentical twins was so high. Identical twins are normally identical in just about EVERYTHING so the fact that only one of a pair of identical twins tends to be homosexual is most telling. It is just about as good a proof of NON-genetic causation as you can get. The idea that homosexuality is caused by such environmental influences as poor social skills or a female-dominated home would seem to be ruled out by the twin studies too as identical twins also tend to have a very similar environment as well as identical genes. There is another article by Cochran here setting out his thinking on the matter. Basically, he says that if genes and upbringing don't make you homosexual, viruses probably do. You can actually "catch" homosexuality. If ever his theories become widely known, I think his life will be in danger. At the least there would be attempts to lock him up for "hate speech".

I think, however, that he overlooks an important third possibility -- inadequate nutrition in utero. And, strangely, that could also explain the discordant findings among monozygotic twins -- via intra-uterine competition. Intra-uterine competition? Sometimes identical twins will come out looking very different because some accident of placenta placement has caused one twin to get a far better supply of blood and its nutrients than the other twin got. And if homosexuality is caused by an abnormality of fetal brain development -- as has often been suggested -- poor fetal nutrition generally (including that caused by intra-uterine competition) could be the cause of it. So I wouldn't start dodging all contact with homosexuals yet.

There is another report here which failed to find a "gay gene". Excerpt: "In summary, the Mustanski study finds no significant relationship between DNA regions and self-reported sexual orientation"



2019 UPDATE: Although it has a certain theoretical elegance, Cochran's virus theory of homesexuality seems to have remained unique to him.. No such virus seems to have emerged. That homexuality emerged due to SOME environmental cause is hard to avoid in the light of the twin data, however. Intra-uterine competition remains the favoured theory but there have also by now emerged some reports of "bump on the head" events that have caused normals to emerge after the accident as homosexual. So random events of brain damage would seem to explain at least some homosexuality. Perinatal events generally would seem to be a lively possibility -- brain damage during delivery being an obvious category there

The central problem may be a taxonomic one, however. Is there such a thing as one type of homosexuality? A lively possibility would seem to be that some incels solve their problem by going gay. Some homosexuals are, in a word, driven to it by social inadequacy. So there is almost certainly not one cause of homosexuality but several. We may need a well developed taxonomy (classification) of homosexuals before research into causes of homosexuality can progresss. An obvious first step would be to consider separately male homosexuals who exhibit female mannerisms and those who do not.




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