Gayness May Be Linked to Conditions in Womb

Interesting read over at the BBC. As usual, I'm interested in the Org's take on the matter.

Spoiler Alert, click show to read: 

Womb environment 'makes men gay'

A man's sexual orientation may be determined by conditions in the womb, according to a study.

Previous research had revealed the more older brothers a boy has, the more likely he is to be gay, but the reason for this phenomenon was unknown.

But a Canadian study has shown that the effect is most likely down to biological rather than social factors.

The research is published in the journal of the Proceedings of the National Academy of Sciences.

Professor Anthony Bogaert from Brock University in Ontario, Canada, studied 944 heterosexual and homosexual men with either "biological" brothers, in this case those who share the same mother, or "non-biological" brothers, that is, adopted, step or half siblings.

He found the link between the number of older brothers and homosexuality only existed when the siblings shared the same mother.

The amount of time the individual spent being raised with older brothers did not affect their sexual orientation.

'Maternal memory'

Writing in the journal, Professor Bogaert said: "If rearing or social factors associated with older male siblings underlies the fraternal birth-order effect [the link between the number of older brothers and male homosexuality], then the number of non-biological older brothers should predict men's sexual orientation, but they do not.

"These results support a prenatal origin to sexual orientation development in men."

He suggests the effect is probably the result of a "maternal memory" in the womb for male births.

A woman's body may see a male foetus as "foreign", he says, prompting an immune reaction which may grow progressively stronger with each male child.

The antibodies created may affect the developing male brain.

In an accompanying article, scientists from Michigan State University said: "These data strengthen the notion that the common denominator between biological brothers, the mother, provides a prenatal environment that fosters homosexuality in her younger sons."

"But the question of mechanism remains."

Andy Forrest, a spokesman for gay rights group Stonewall, said: "Increasingly, credible evidence appears to indicate that being gay is genetically determined rather than being a so-called lifestyle choice.

"It adds further weight to the argument that lesbian and gay people should be treated equally in society and not discriminated against for something that's just as inherent as skin colour."

What can I say? Lucky that I'm the firstborn son.

:sweatdrop:

Hmm... interesting.

Well, the activist, as usual has jumped on it in the wrong way. It suggests its not genetic and it's actually your mother's fault.

They need to work out if a similar pattern holds true for female homosexuality.

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Originally Posted by Wigferth Ironwall

It suggests its not genetic and it's actually your mother's fault.

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Blame it on mom, everything is the mothers fault! ~D

Well, technically it would be "blame it on mom's uterus and immune system." But that's assuming that we know the causal link between womb conditions and gayness, and we don't. Still, it's always satisfying to blame everything on mum.

Hmmm. Actually thats quite interesting. I'm the 3rd Born of my three brothers, My Older Two Brothers and Myself Came out Quite Normal, my Younger Brother is gay.

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Originally Posted by Wigferth Ironwall

Well, the activist, as usual has jumped on it in the wrong way. It suggests its not genetic and it's actually your mother's fault.

They need to work out if a similar pattern holds true for female homosexuality.

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They say not, because they think that it is the male Y chromosome that triggers an immuno-reaction in the woman's body which builds up strength with successive pregnancies. Naturally, this does not occur with a female foetus.

I know at least two cases where the younger brother (of two) is the straight one. I also know some single children that are gay. This is interesting, but a weak (causal ?) correlation at most.

I don't know if your experience really nixes the study, Doc Bean. 944 is a decent-sized sample for this sort of research. And if gayness is linked to womb conditions, who's to say such a situation can't occur in a different order? Human bodies are infinitely variable, after all.

It's the closest I've seen to meaningful research on the origins of gayness, and that alone makes it noteworthy.

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Originally Posted by Lemur

I don't know if your experience really nixes the study, Doc Bean. 944 is a decent-sized sample for this sort of research. And if gayness is linked to womb conditions, who's to say such a situation can't occur in a different order? Human bodies are infinitely variable, after all.

It's the closest I've seen to meaningful research on the origins of gayness, and that alone makes it noteworthy.

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I said it was interesting, but it should be seen in context, it can only partially explain gayness (which is a huge step of course). Also I don't like the biological reasoning that much, if it was the mothers immune system causing it then homosexual children should be born 'weaker' than heterosexual children. This should certainly be investigated further before drawing any conclusions about the actual cause. So far I only see a correlation, an interesting one, but not necessarily a causal relationship.

Is it just me, or does anybody else kind of giggle to themselves when they hear the word "gayness?"

:laugh4:

That depends. When you say "giggle," do you mean a light, girlish titter?

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Originally Posted by Lemur

That depends. When you say "giggle," do you mean a light, girlish titter?

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I'd rather not answer that question, thank you very much...

:shame:

PS: You said "titter."

a deep, masculine guffaw?


edit: btw, i haven't read the study yet, but i noticed that it's using youngest half-brothers (presumeably with different mothers), adopted and step brothers to contrast the maternal brothers.. but how much does it account for potential differences in the ways that these "non-biological" brothers may be raised versus the upbringing for maternal brothers?

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"It adds further weight to the argument that lesbian and gay people should be treated equally in society and not discriminated against for something that's just as inherent as skin colour."

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I wish guy rights activists would say such things.

I don't know A.Saturnus, you would fist have to prove that manliness is pre-determined. A study I read says there's a 99.999% chance that XY chromosome fetuses will turn out male, but that's just a (albeit interesting) correlation.

As it stands having a penis is a lifestyle choice.

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Increasingly, credible evidence appears to indicate that being gay is genetically determined rather than being a so-called lifestyle choice.

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Genetically determined or not, that is still not a legitimate exscuse.

I think it is possible that gayness is linked to conditions in the womb, but morseo based on what corrupt chemicals get into the baby's body and cause brain & other defects to develop.

I bet it is directly related to the toxic crap in the food and water supply.

Actually, that quote about "genetically determined" seems to be more and more off the mark. Looks as though gayness may be hormonally determined, and at the fetal stage. But there's no proof and no causation yet, just a statistical correlation. We're a long way from knowing what causes what.

As your theory that chemicals and pollutants may be causal, Nav, that would do little to explain pre-industrial examples of homosexuality.

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Originally Posted by Navaros

Genetically determined or not, that is still not a legitimate exscuse.

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I fail to see where any legitimate excuse would be necessary. Going by this article, that'd be like me having to provide a "legitimate excuse" for having blue eyes...

Just a wacky thought -- might this not be an overpopulation control built in by evolution? In other words, if a woman is having ten babies, wouldn't there be a survival advantage to her group and/or tribe by having the later ones be unlikely to breed, but rather contribute to the group without taking resources for their own babies?

Maybe this is all part of the plan ...

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Originally Posted by Watchman

I fail to see where any legitimate excuse would be necessary. Going by this article, that'd be like me having to provide a "legitimate excuse" for having blue eyes...

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Why do people even bother discussing this with Navaros ? :dizzy2:

I'm bored and have nothing better to do than poke at him. So sue me. :balloon2:

It would make more sense to put such a restriction on females then wouldn't it?
Besides, there is overpopulation control in nature. 1) natural predators 2) if 1 is absent, epidemics

Scarcity means that there will inevitably only be enough to sustain X number of specimens, individually it would make more sense for you to breed harder to take up as many places as you can (and thus ensure your genetic survival)

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Originally Posted by Lemur

Actually, that quote about "genetically determined" seems to be more and more off the mark. Looks as though gayness may be hormonally determined, and at the fetal stage.

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there are external factors that control the production of hormones too, but genetics certainly plays a large role in hormonal expression.

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As your theory that chemicals and pollutants may be causal, Nav, that would do little to explain pre-industrial examples of homosexuality.

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while navaros' "theory" is quite.. queer*.. there are natural 'pollutants'. plant-based poisons have been used as medicines/drugs/etc since forever. and heavy metals have been a problem since mining developed (e.g. lead poisoning in ancient rome). just fyi.






*cheeky, aren't i?

I have some concerns about the study itself. Anthony Bogaert is a psychologist and professor of community health sciences. He did a statistical study and then made pronouncements about genetics and cellular biology. I find that rather odd. He is neither a geneticist nor a cellular biologist. Statements like:

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A woman's body may see a male foetus as "foreign", he says, prompting an immune reaction which may grow progressively stronger with each male child.

The antibodies created may affect the developing male brain.

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We are extremely far from even beginning to understand the processes involved between mother and foetus and the immuno-response. Transposons, retrotranposons, the proteome, viral fragments, introns and more all play a very poorly understand part at the placental barrier. And yet, here's a psychologist making pronouncements about the genetic and cellular biology involved? I don't think so.

Worse yet, Bogaert has a history of pushing this view. He's associated with the Clarke Institute in Canada, which has a rather sordid reputation.

I say take it with a huge grain of salt, and let the real scientists weigh in on the matter before accepting it as anything even approaching valid.

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Originally Posted by Aenlic

He is neither a geneticist nor a cellular biologist. Statements like:

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aenlic, he did use the modifier "may". calm down eh? ~;)

but you're right, all of this study should be taken with a grain of salt. i imagine that's true with many socio-biology studies..

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Originally Posted by Big_John

aenlic, he did use the modifier "may". calm down eh? ~;)

but you're right, all of this study should be taken with a grain of salt. i imagine that's true with many socio-biology studies..

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Pretty much all socio-biological studies. Most are based on a flimsy explanation for vague trends in a sample which is clearly too small/specific to be applied over an entire population. It's amazing what you can do with statistics too.

Does fraternal twins count?

I always get a sort of itchy feeling when people start reverting to biology (or, for that matter, economy; of the "hard" sciences these seem the ones mainly involved) to explain social, cultural and psychological things.
I think one of my textbooks had an expression for it.
...
:idea2:
Oh yeah. "The mortal sin of reductionism".