Many men are gay because of biological differences wrought by their mothers before the boys were born, according to a study that opens a new and contentious front in the same-sex marriage wars.As the FC noted with a sigh after she sent this on to me, "It's always the mother."
Anthony F. Bogaert of Brock University in Ontario had already documented that boys who have several older brothers are more likely than others to grow up gay -- a phenomenon known as the fraternal birth order effect.
But why? Some scientists have suspected social and environmental factors, such as the large amount of time such boys spend fraternizing with male siblings during their sexual development. Others have wondered whether, after carrying multiple male fetuses, women undergo biological changes that affect the development of brain areas related to sexual orientation in subsequent sons.
[...]
The mechanism behind this apparent maternal alchemy remains a mystery. But many scientists suspect that women mount a subtle immune system response against male fetuses that becomes stronger with each male pregnancy, ultimately affecting fetal brains in ways that influence sexual orientation.
I'm the second son of three, and third in the birth order in the family (the oldest being my sister). So if it's true that the more older brothers a man has the more likely he is to be gay, I have some rather upsetting news for my ragingly heterosexual younger brother, the father of three kids.
So let's run an informal survey among the men out there: if you're gay, how many older brothers do you have? If you're straight, same question.
