The finding makes clear evidence that sexual orientation was set in the womb. The reason the scientists decided to finally scan the brains and look for the source of the differences was that they had noticed that homosexual people of both sexes had differences in certain cognitive abilities, suggesting there may be subtle differences in their brain structures.
Karolinska Institute scientists scanned a group of 90 healthy gay and heterosexual men and women to measure the volume of both sides, or hemispheres, of their brain. The scan results showed that lesbians and heterosexual men shared a particular "asymmetry" in their hemisphere size, while heterosexual women and gay men had no difference between the size of the different halves of their brain. In other words, the brains of gay men were more like heterosexual women, and gay women more like heterosexual men.
Further experiments found something else - other significant differences in one particular area of the brain, the amygdale. In heterosexual men and gay women, more nerve "connections" were spotted in the right side of the amygdale than in the left while homosexual men and heterosexual women had more neural connections in the left amygdale.
Some scientists believe now that these brain differences were laid down early in fetal development and that if you are gay, you are born gay.
The amygdale is important because of its role in "orientating", or directing, the rest of the brain in response to an emotional stimulus - be it during the "fight or flight" response, or the presence of a potential mate. This means that the brain network that determines what sexual orientation actually 'orients' towards is similar between gay men and straight women, and between gay women and straight men.
Dont remember how I got to this website, but my god I'm glad that I just read that. Thank you for posting. I feel relieved that there is proof that its not a choice to be gay or straight! Do you know any thing about bi-sexual brains; maybe it'll stop people from saying that there's no such thing as bisexual :P