Nigel Campbell's picture

Are Men With Older Brothers More Likely To Be Gay? New Research!

Interesting new research is taking place regarding a 2006 study led by Anthony Bogaert, Community Health Sciences chair and professor at Ontario's Brock University, that theorized that homosexuality can be impacted by fraternal birth order. According to Bogaert's research "having more older brothers makes it more likely a man will be gay. Each older brother raises the odds of homosexuality by a third, potentially going from a 3 percent chance with the first son to a 6 percent chance with the fourth."
Basically the more older brothers you have, the more likely you are to play for our team.
An abstract from the 2006 research, published by Proceedings of the National Academy of Sciences reads:
"Only biological older brothers, and not any other sibling characteristic, including nonbiological older brothers, predicted men’s sexual orientation, regardless of the amount of time reared with these siblings. These results strongly suggest a prenatal origin to the fraternal birth-order effect."

Today, Bogaert is looking to determine that prenatal origin.

"[The 2006 study] was an important study and it does suggest there is probably a biological basis to the older brother effect," he told The Huffington Post during a phone conversation from Canada Thursday afternoon. "It's an important study in the context of sex orientation development. We have additional research going on right now testing specifically the underlying biological effect of the older brother. ... There are no results yet. We are collecting samples of mothers of gay men and comparing them to mothers of heterosexual men and looking to see if there is evidence of a biological factor that differs between the two groups."

Bogaert explained that the 2006 study never determined a specific "mechanism" -- a biological factor or process -- behind the older brother effect. He suggested this mechanism could be a maternal immune response, a hormone change in the womb, a gestational factor during pregnancy or even genes.

"The 2006 study really strongly suggests that there is biological mechanism but it never really tested the specific mechanism itself in terms of determining what factor is in fact influencing a change in a mother's development during pregnancy," he explained to HuffPost. "What we're doing now is we're looking at the specific mechanism and seeing if we can find evidence for that. We have a study looking at ... mothers of gay and heterosexual men and seeing if there is a maternal immune response. So, that's something very unique and new."

Bogaert says that isolating the exact biological mechanism or process will support the "nature" side of the Nature v. Nurture debate. If successful, his new research could provide a biological backing for homosexuality.

"I think there's strong evidence that people who believe that there's a biological basis to sexual orientation tend to be more tolerant to sexual minorities, and that's one of the more positive [possible] social outcomes," he said. "And I am in that camp. I don't believe that homosexuality is a disorder or immoral."


What do you make of this proposed biological connection, Instincters? (And what could these findings mean for those of us without older male siblings??)


Image Source   (H/T: HuffPo)


Oh, yes, I am the middle of 5 children and the only gay one.

Both Bob, my husband, and I have an older brother.  Now we know why we are gay.  Thank God for that.

My partner is the oldest of 8, 5 boys and 3 girls (all the boys are younger). He is the only gay one of the brood. I'm the youngest of 3 boys and all 3 of us are gay! A friend of ours is the oldest of his family... 7 guys and 1 girl (youngest) and none of them are gay at all. He and his family are very gay friendly so none of them are stuck in the closet. I'm sure there are other similar families out there in the same boat. This is just another example of inaccurate research providing inadvertently skewed data.

While gay men may not care, this kind of research puts another nail in the coffin of the tired religious doctrine so much of the world uses to discriminate against us.

I think this is pointless.  Who cares about these fantasy reasons for people being who they are?

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