A new study shows that men who have older biological brothers, are more likely to be gay than those who don’t. The more older brothers he has, the greater the likelihood is.
“The link between having older brothers and homosexuality has long been established, but the new findings indicate firmly that conditions in the womb before birth, and not the subsequent family environment, are responsible.”
It’s yet unknown what those conditions may be, though there is speculation they may be related to the way the mother’s immune system reacts to carrying male foetuses. The Y chromosone in the male foestuses may be recognized as foreign and generate a stronger immune response, which increases which each subsequent pregnancy.
Below is the article from the Times on the study.


Gay men are ‘born with big brothers’
By Mark Henderson
From Times Online: http://www.timesonline.co.uk/article/0,,11069-2244488,00.html
Some sexual orientation may be determined by the maternal response to carrying male foetuses
A MAN