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