March 24, 2009

Commenter Bill's chimerism theory of the origins of homosexuality

One of the bigger holes in the social sciences is that we have do not have a definitive explanation of why some people are homosexual. Bill, a frequent commenter on this blog, has posted on his Welmer blog his theory that homosexuality tends to originate in the creepy-sounding phenomenon of chimerism, which he sees as an alternative to Greg Cochran's Gay Germ Theory.
The Chimera Hypothesis: Homosexuality and Plural Pregnancy

29 comments:

CJ said...

Here's a direct link to the post you reference:

The Chimera Hypothesis: Homosexuality and Plural Pregnancy

I think you meant to type no definitive explanation. But, a very interesting subject. I'm left-handed, have a counterclockwise hair whorl, and like opera -- but have no more interest in homosexual relationships than I do in eating cardboard. Time to read up a little on chimerism.

Anonymous said...

Lesbianism in Stumptailed Macaques:


http://www.youtube.com/watch?v=Nd4Hbq-syQI



Why are these little Japanese Apes lesbians? Anybody venture a guess?

Bill said...

I think you meant to type no definitive explanation. But, a very interesting subject. I'm left-handed, have a counterclockwise hair whorl, and like opera -- but have no more interest in homosexual relationships than I do in eating cardboard. Time to read up a little on chimerism.

If your left-handedness and counterclockwise hair whorl are due to a vanished twin, it may have been a male. I think it's guys with female vanished twins who are more likely to be homosexual.

Anonymous said...

Lesbianism in Stumptailed Macaques

I haven't thought "this would be a great rock band name" in years, but the name "Stumptailed Macaques" forced me to.

Mark Wethman said...

I shared a cab the other day with a friend of a friend (all three of us are gay). I told him I work for an adoption agency, and he brought up the fact that he was adopted, which led to a discussion of his background, including the fact that he had a twin who died in the womb, and the doctors know this because he has tiny, extra teeth embedded in his skull from absorbing him/her. I responded by gushing about the chimeric theory of homosexuality. Interestingly, my friend has an autoimmune disorder that prevents him from eating wheat, and he said that he was always predisposed to the autoimmune theory of homosexuality (which, if I recall correctly, suggests that the mother's immune system attacks the male fetus and derails the masculinization process somehow). Incidentally, autoimmune disorders run in my family on my mom's side, too. It shouldn't be too hard to see if there's a correlation between homosexuality and such disorders.

rbc said...

I don't think we can achieve a satisfactory understanding of human homosexuality without also explaining the homosexual behavior which is observed in other species -- many of which (fish, birds) don't have placentas, and some of which (insects) don't even really have brains.

The view I favor is that the evolutionary position of homosexuality is akin to that of sickle cell anemia -- having all the genes for the condition reduces overall fertility, but having just some of them increases it. The intermediate adaptive condition for homosexuality would then be some degree of androgyny, perhaps including bisexuality. But how would that help?

I have heard it argued that bisexuals make better mates because they better understand an opposite sex partner's desires. That is not what I am trying to say here. I am driving at something applicable to far more species, and far older, evolutionarily. I am talking about sexual camouflage.

In many species, a large group of females is reproductively monopolized by a single male, who must spend nearly all his time defending them from competitors. The most obvious strategy is to become a bigger, stronger male, and beat the alpha in direct confrontation. Another strategy exists, and is well attested as low down the chain as among insects -- a relatively small and weak male who has no chance in direct conflict pretends to be a female, even to the point of offering to be mounted by the dominant male, in order to sneak into the harem. Once there, the female-acting male then mates with the true females he is hiding among, while the alpha's attention is directed outward again. Note also that in this case, the alpha male is actually protecting the interloper from interference by other tough guys, at least as much as he is defending his own reproductive interests.

In many other species, females defend themselves, selecting a small number of mates from the many males who offer themselves. One very effective strategy, again often observed in the wild, for driving off unwanted males is to pretend to be one. Then they leave you alone, and you can pick the one you want at your leisure.

I certainly do not think that either of these strategies is at work among actual homosexuals, but I am pretty sure I have seen modified versions of both of them attempted among heterosexual college students. In any case, whether or not they are still part of the human behavioral repertoire, they are part of the ancient biological heritage we share with other, nonmammalian, species, who also exhibit homosexual behavior at much the same rates humans do.

Peter Frost said...

Exclusive male homosexuality is probably due to incomplete masculinization of the male brain during prenatal or neonatal development. This process may be aborted by such factors as a microbe, a malfunctioning gene, or exposure to anti-androgens (e.g., estrogens or estrogenic compounds).

For this process to abort, it isn't enough to have 'female' cells somewhere in the male body. These cells must be positioned at a critical point on the developmental pathway of cerebral masculinization. Otherwise, they will develop just like a 'male' cell would.

But there is a more fundamental objection to the chimerism theory: chimerism is nothing new. The human organism has therefore had eons of evolutionary time to adjust to it.

I suspect that a very low baseline of exclusive male homosexuality (less than 1% of all men) is due to chimerism or to random genetic mutations that haven't been weeded out yet by natural selection. In most cases, it is probably due to something novel in the environment (e.g., environmental estrogens) or to some kind of microbe (e.g., Cochran's theory).

Gabe said...

I haven't thought "this would be a great rock band name" in years, but the name "Stumptailed Macaques" forced me to.

I've long been partial to the "Sooty Mangabeys." Especially if the lads were to hail from coal-mining families in Newcastle....

Anonymous said...

Some possible evidence in favor of germ and/or autoimmune theories:

Arch Sex Behav. 2008 Feb;37(1):145-9.Click here to read Links
Eye color, hair color, blood type, and the rhesus factor: exploring possible genetic links to sexual orientation.
Ellis L, Ficek C, Burke D, Das S.

Department of Sociology, Minot State University, Minot, ND 58707, USA. lee.ellis@minotstateu.edu

The present study sought to expand the limited evidence that sexual orientation is influenced by genetic factors. This was accomplished by seeking statistical differences between heterosexuals and homosexuals for four traits that are known to be genetically determined: eye color, natural hair color, blood type, and the Rhesus factor. Using a sample of over 7,000 U.S. and Canadian college students supplemented with additional homosexual subjects obtained through internet contacts, we found no significant differences between heterosexuals and homosexuals regarding eye color or hair color. In the case of blood type and the Rh factor, however, interesting patterns emerged. Heterosexual males and females exhibited statistically identical frequencies of the A blood type, while gay men exhibited a relatively low incidence and lesbians had a relatively high incidence (p < .05). In the case of the Rh factor, unusually high proportions of homosexuals of both sexes were Rh- when compared to heterosexuals (p < .06). The findings suggest that a connection may exist between sexual orientation and genes both on chromosome 9 (where blood type is determined) and on chromosome 1 (where the Rh factor is regulated).

PMID: 18074215 [PubMed - indexed for MEDLINE]

gordon-bennett said...

Now that we have found what causes homosexuality, can we get on apace with finding the cure?

Anonymous said...

Mark,
My mom's side of the family is filled with autoimmune diseases and I'm gay.

as said...

So, Welmer is saying that some females naturally do what fertility meds do, that is, pump out a bunch of eggs and then selectively abort them. And chimerism is a side effect of this natural fertility boosting treatment?

So, do women who use fertility drugs have high rates of chimerism? Do the resulting children have high rates of chimerism, homosexuality, left handedness, and left handed whorls?

Glaivester said...

I don't think we can achieve a satisfactory understanding of human homosexuality without also explaining the homosexual behavior which is observed in other species

I don't think that the issue is homosexual behavior as much as exclusive homosexual orientation.

SFG said...

We don't know what causes it. I heard one theory that works for lesbians at least: a gene that makes you want to have sex with women will pay off in your male offspring even if it occasionally turns one of your daughters gay.

Not so clear for gays: women gain little benefit from increased sexual drive in the reproductive sense.

Debbie said...

While I prefer men for sex, I often find them boorish companions. Does wanting them to go away or die after mating make me a lesbian?

benjack said...

What you need to do here is cross out the word "homosexuality" and replace it with "transgenderism", which is what is really being measured. The homosexual preference/behavior is really just an epiphenomenon of the reversal of brain gender.

People have engaged in homosexual behavior and/or had homosexual feelings without brain gender reversal, since time immemorial, for various reasons, but these people do not seem to be the type who currently identify as "gay" in the modern West. (For instance, according to Gibbon, all of the first 15 Roman Emperors, except Claudius, apparently liked to take boys as lovers, even when women were obviously available. I doubt the majority of these emperors would exhibit the transgender traits seen among most "gays", as detailed, for instance, in J.Micheal Baileys Man Who Would Be Queen. Or did royal inbreeding lead to run-amok Chimerism producing a parade of pansies on the throne? Somehow I doubt it )
Transgenderism (mild or extreme) may be the result of Chimerism. Homosexual behavior, and even preference, may not.

Anonymous said...

"While I prefer men for sex, I often find them boorish companions. Does wanting them to go away or die after mating make me a lesbian?"

Probably not. But don't watch too many Theresa Russell films...

PS: let me know if you live in the NYC area. I'll happily leave quickly after sex. And uh, post a photo.

Bill said...

So, Welmer is saying that some females naturally do what fertility meds do, that is, pump out a bunch of eggs and then selectively abort them. And chimerism is a side effect of this natural fertility boosting treatment?

Something like that. But apparently the selective abortions have more to do with the paternal genes. There appears to be a characteristic of the paternal X chromosome in some populations that retards the growth of female embryos, making them more likely to be pushed aside by male embryos. This effect is strongest in Asians and weakest in Africans, hence the higher male/female birth ratios in Asian populations and lower in African.

So, do women who use fertility drugs have high rates of chimerism? Do the resulting children have high rates of chimerism, homosexuality, left handedness, and left handed whorls?

I'm not sure whether the research has come out on that yet, but I'd be willing to bet that they do. In fact, I think the autism epidemic is related to fertility drugs, and there is a strong association between autism and chimerism/mosaicism, as suggested by the very high rate of Blaschko's lines on autistic children.

Zoe Brain said...

Something that attempts to draw various strands of research together is BiGender and the Brain.

References to
Prenatal exposure to testosterone and functional cerebral lateralization: a study in same-sex and opposite-sex twin girls. by Cohen-Bendehan et al;
Prenatal exposure to diethylstilbestrol(DES) in males and gender-related disorders:results from a 5-year study by Kerlin;
Gender change in 46,XY persons with 5alpha-reductase-2 deficiency and 17beta-hydroxysteroid dehydrogenase-3 deficiency. by Cohen-Ketternis:
Biased-Interaction Theory of Psychosexual Development: “How Does One Know if One is Male or Female?” by Diamond:

...and more.

Moses said...

"Another strategy exists, and is well attested as low down the chain as among insects -- a relatively small and weak male who has no chance in direct conflict pretends to be a female, even to the point of offering to be mounted by the dominant male, in order to sneak into the harem."

Think of the story of smooth, clever Jacob and his hairy, wild twin Esau. Feminine Jacob wins out over masculine Esau and gets the patriarch's birthright. Remember this story happened in the context of a goat herding kin network, not a nuclear family unit.

It's too bad that the evolution crowd is so Bible averse, because it's gold mine of superior evolutionary strategies. Abrahamic societies consistently out-compete more diffuse paganistic or (modern times) atheistic ones.

That's in the story too: the patriarch Isaac suspects Jacob's deception because Jacob evokes the name of God, and "Esau never mentions God."

Maybe muted masculinity in males has evolutionary advantages. Guys who are a little femmy might make better dads who invest more in teaching and providing for their offspring. Blacks always criticize white men as "not real men" because they let women dominate them.

As moderns we focus too much on the sexual act as what's "really" happening, but that is an odd or even stupid view. Sex means reproduction. Even the Darwin crowd neglects to really grasp that. If a man is a high investment parent with many offspring, occasional male-male sex contact is not too relevant (except in re increased pathogen risk).

There is a big difference between discreet taboo-breaking and overt, socially disruptive rule taboo-breaking. We moderns are too daft to know the difference, but the smart guys who wrote the Bible maybe were a little more canny about human nature.

albertosaurus said...

There is speculation and then there is testing.

As most of the people who read this blog would know, before the spirochete was found there were plenty of speculators who wrote that spyhlis was caused by some form of insubstantial or spiritual immorality. Bad or immoral behavior itself was thought to cause the disease, not anything physical.

Similarly although the connection between swamps and malaria was known for millenia, until quite recently the disease was thought to be spread by some kind of insubstantial miasma. Sort of like the lumeniferous ether.

Tuberculousis was thought to be non infectious altogether. Some said to be a product of vampirism. TB was so common that saloons and private homes had spitoons for the tuberculars to expectorate. TB was everywhere and was killing everyone but no one suspected that a microorganism was involved.

The strange history of the popular discourse about these diseases is what makes Cochran's hypothesis at least plausible. Before a bug is isolated all sorts of wild and loony explanations are floated.

The Chimera Hypothesis may or may not be another just fanciful explanation.

On the popular medical TV series House last year his patient of the week was discovered to be a chimera when two different samples were shown to have different DNA patterns.

BTW on House chimerism didn't cause homosexuality but rather caused its victims to see space aliens. Both space aliens and male homosexuals seem focused on anal probes, but that is probably just a cooincidence.

Multiple minor biopsies or swabs for DNA could be done and they should show chimerism if it is there.

Unless I'm missing something this hypothesis could be proved or disproved in a couple weeks at any clinic in the country. Just test a group of homosexuals and a group of heterosexual controls.

Vic Braeden used to say,"Famous by Thursday". In this circumstance this hypothesis could be "Confirmed or disproven by the Memorial Day".

Anonymous said...

Steve,
Thanks so much for bringing up this post and his blog.

It is one of the most exciting things I've read in a very long time. It's up there with "The New Germ Theory".

Also, I had never heard of chimeras. That, more than the focus on just homosexuality, was really eye opening. I also know I'm not the only one as in all the years I've been reading you and the threads, I don't recall them ever being brought up to explain anything. Perhaps Frost or Cochran has brought them up, but chimeras have not been a mainstream point of discussion here in the Stevosphere. So, I think a little humility is in order for the rest of us. Bill is clearly extraordinarily intelligent.

Sideways said...

If this hypothesis were correct, rates of homosexuality by race would pretty much have to reflect in some way rates of dizygotic twinning by race.

michael farris said...

I'm still not convinced that human homosexual activity is anything that needs to be 'explained' any more than whistling or square dancing or checkers need to be explained.

When you strip away the family values or evolutionary or gay rights histeria, homosexual activity is just the co-occurence of two traits that are separate but widely dispersed in humanity:

a) enjoyment of recreational sex

b) emotional bonding with members of the same sex.

Neither is especially noteworthy or exceptional on its own, it's just that for the majority both drives (sexual pleasure and same-sex bonding) can't be satisfied at the same time while for a minority they can and for an even smaller minority they _have_ to co-occur.

Of the two, I think most people concentrate on a) when the really interesting stuff is in b).
Gay men don't like anal sex because they're attracted to assholes. They like anal sex because it gives them the possibility of penetration (linked in the male psyche with the greatest degree of intimacy) with other men.

To draw a (very rough) analogy with my field of linguistics. Homosexuality is a little like Hungarian; there's no one feature that's especially unique, what's unusual is that the particular features happening in the same language.

Bill said...

Albertosaurus

Unless I'm missing something this hypothesis could be proved or disproved in a couple weeks at any clinic in the country. Just test a group of homosexuals and a group of heterosexual controls.


I think it would take full autopsies, because chimerism isn't usually present in every tissue (e.g. it is very rare in reproductive organs in humans, but not marmosets). That's what I'd suggest: examine homosexual cadavers like Simon LeVay did.


BTW on House chimerism didn't cause homosexuality but rather caused its victims to see space aliens.


Which suggests it does have neurological implications. I'm glad you brought that up.

Both space aliens and male homosexuals seem focused on anal probes, but that is probably just a cooincidence.

Maybe, but maybe not.

Sideways said...

If this hypothesis were correct, rates of homosexuality by race would pretty much have to reflect in some way rates of dizygotic twinning by race.


Richard Burton's "Sotadic Zone" (from the 19th century) very closely matches populations where the male/female birth ratio is highest, and fewer twins make it to term. Very interesting correlation, I thought.

Svigor said...

but the smart guys who wrote the Bible maybe were a little more canny about human nature.

That's quite an understatement. The OT is the world's pioneering work on ethnic nationalism (AKA "racism," "race realism," what have you).

Reg Cæsar said...

I don't think that the issue is homosexual behavior as much as exclusive homosexual orientation. --Glaivester

Yes, it's not so much the homophilia, but the heterophobia. Or, as I once saw scribbled on a university (men's) bathroom stall, "I'd rather die than go to bed with a woman." I doubt this was John the Baptist speaking.

The view I favor is that the evolutionary position of homosexuality is akin to that of sickle cell anemia... --RBC ('really big cojones'?)

Sickle-cell occurred to me as well-- one good, two bad. But that's one factor. There is plenty of room for 'combo' theories, where two factors meet, resulting in a phenomenon which neither alone would create.

E.g., say inborn 'openness' (rather than 'prediliction') to homoerotic deviation (sorry, but 'homosexual' is so oxymoronic) might occur in 10% of boys. Another 10% of boys grow up in a 'Freudian' environment. If these two factors correlate randomly, then 10% of 10% leads to 1% and *poof*-- you get a poof.

And if either factor leads to more reproduction working alone, that may counteract the deadening effect of them working together.

Don't forget, too, that in most places in most times, most people were expected to marry and have children. Many 'innate' homos just had to suck it up and breed. I have a lesbian relative (now in her 70s) who married and had five kids before she 'came out'. Her boomer nephew didn't bother with the first step! Those two responses lead to somewhat different future generations.

Ironically, gay rights may be what finally kills off gays.

Reg Cæsar said...

I haven't thought "this would be a great rock band name" in years, but the name "Stumptailed Macaques" forced me to. --anonymous

I believe former Sen. George Allen holds the trademark on that one.

Anonymous said...

i'm gonna make my own post about it