Study: Men With Older Brothers More Likely to Be Gay

[Marc]

Lol, I have an older brother from the same mother.

http://www.comcast.net/news/health/i...l&cvqh=itn_gay

Men With Older Brothers More Likely to Be Gay
By RANDOLPH E. SCHMID, Associated Press Writer


WASHINGTON - Having several older brothers increases the likelihood of a man being gay, a finding researchers say adds weight to the idea that there is a biological basis for sexual orientation.

"It's likely to be a prenatal effect," said Anthony F. Bogaert of Brock University in St. Catharines, Canada, "This and other studies suggest that there is probably a biological basis for" homosexuality.

S. Marc Breedlove of Michigan State University said the finding "absolutely" confirms a physical basis.

"Anybody's first guess would have been that the older brothers were having an effect socially, but this data doesn't support that," Breedlove said in a telephone interview.

The only link between the brothers is the mother and so the effect has to be through the mother, especially since stepbrothers didn't have the effect, said Breedlove, who was not part of the research.

Bogaert studied four groups of Canadian men, a total of 944 people, analyzing the number of brothers and sisters each had, whether or not they lived with those siblings and whether the siblings were related by blood or adopted.

He reports in a paper appearing in Tuesday's issue of Proceedings of the National Academy of Sciences that having several biological older brothers increased the chance of a man being gay.

It's an effect that can be detected with one older brother and becomes stronger with three or four or more, Bogaert said in a telephone interview.

But, he added, this needs to be looked at in context of the overall rate of homosexuality in men, which he suggested is about 3 percent. With several older brothers the rate may increase from 3 percent to 5 percent, he said, but that still means 95 percent of men with several older brothers are heterosexual.

The effect of birth order on male homosexuality has been reported previously but Bogaert's work is the first designed to rule out social or environmental effects.

Bogaert said he concluded the effect was biological by comparing men with biological brothers to those with brothers to whom they were not biologically related.

The increase in the likelihood of being gay was seen only in those whose brothers had the same mothers, whether they were raised together or not, he said.

Men raised with several older step- or adopted brothers do not have an increased chance of being gay.

"So what that means is that the environment a person is raised in really makes not much difference," he said.

What makes a difference, he said, is having older brothers who shared the same womb and gestational experience, suggesting the difference is because of "some sort of prenatal factor."

One possibility, he suggests, is a maternal immune response to succeeding male fetuses. The mother may react to a male fetus as foreign but not to a female fetus because the mother is also female.

It might be like the maternal immune response that can occur when a mother has Rh-negative blood but her fetus has Rh-positive blood. Without treatment, the mother can develop antibodies that may attack the fetus during future pregnancies.

Whether that's what is happening remains to be seen, but it is a provocative hypothesis, said a commentary by Breedlove, David A. Puts and Cynthia L. Jordan, all of Michigan State.

The research was funded by the Social Sciences and Humanities Research Council of Canada.

___

[Lee]

Interesting stuff.

If i recall correctly, there was another study a few years ago that said individuals with more than 1 older sibling had a higher likelyhood of being gay also.

Regards,

Lee

[Marc]

Interesting stuff.

If i recall correctly, there was another study a few years ago that said individuals with more than 1 older sibling had a higher likelyhood of being gay also.

Regards,

Lee

Im the youngest in my family .
My cousin is gay but he was a middle child.

I almost didnt post this because its like a formula for being gay, and you just are what you are. But I am facinated that i do have an older brother and Im the youngest,

[jIgG]

my bf's family is big and they have a lot of gays
at least 2 that i know of from his aunts side of things where there are a lot of kids

[Goldie]

My lesbian sister has an older brother.... me.

But I am the oldest child.

My partner has one sibling... and it is an older brother.

So there might be something to this.. :penny:

[Bec]

Interesting ... as I'm the oldest of 6 - all same mom, but they're all my half brothers and sisters. 4 brothers - all apparently straight (but I reeeeallly think 2 of them - middle boy and youngest - are closet gay), while my sister and I are both lesbian. I think it has more to do with long range big family effect ... my mom also came from a large family ... perhaps genetics steps in as a "normal" birth control way of controlling the population? Especially since we see it in the animal kingdom as well. That might be a more viable way to test the theory if "gayness" kicks in when the population threatens to over extend the availability of food/land to support the species.

[maxpower]

The sample size “four groups of Canadian men, a total of 944 people” and slight above predicted out term “5-6%” just says too me a totally meaningless study, that someone is trying to justify the money spent on/make a name for themselves ECT by getting published.

[robin]

Hmmmm. In my case I'm the oldest of 4. In my hubby's, he's the oldest; Actually, most gay men that I personally know are the oldest in their family. I vote the "study" is skewed. .

[basschick]

my friend was the oldest and 2 of his 3 brothers are also gay. his lover was an only child. and my friend rick was the younger of 2.

i always wonder on studies of this type whether one of the things that is really being measured is the type of person that takes part in studies...

[Jasun]

I'm the oldest boy, but the middle child.

and my little brother is gay too.

[tombarr]

I am the oldest brother in the family and the second oldest of 5. Noone else in my family is gay... (or admits to it... )

I once knew a family in South Carolina where there were 4 boys. All were gay. I know a family from Vancouver of two brothers, both are gay. I know a family in Thailand with 2 boys, both are gay, AND the sister is a lesbian!

I don't think the survey results are indicative of any realistic trend based upon how many siblings or older or younger, I think it is much more genetic than just your position in the ladder of the family.

[maxpower]

Ya I also think its allot more nature than nurture, but the genetic thing does open a whole can of worms that even I an not sure about brining up in a essentially gay forum, but I will say I do agree with the nature argument in this area.

[longboardjim]

i'm really not sure this is "socialogical" but more "genetic" ( joining the navy did not straighten me out! ) something inside just had me ( by force of course ) stimulated more by men than women , i have no regrets ( although i still get turned on thinking of grace jones )

sincerely ~ ..."i'm not perfect"... - grace jones

[ichatnakedgay]

They never have proof of anything. Well maybe they do sometimes. Like when they did that study about that thing. What was it? You know the one where the ... fill in blank ... and the ...

That's the one.:yeah:

[Billaboy]

The interesting thing in this article is that the "older brother" link is seen in gays, but not in lesbians.

Also, the tests they did were also made on some twins who were separated at birth, and they saw the same link (whereas they did not see it in those who had brothers from a different mother), which proves that that genetics truly are behind it.

(This doesn't mean that the environment isn't important though! And it doesn't mean that all gays are gay because of genetics... just that when a guy has older brothers, the chance of him being gay is higher, because of genetics...)

Interesting stuff!!