The evidences continue to build up.
The arrangement of a mother's genes could affect the sexual orientation of her son, according to a new study.
The finding, detailed in the February issue of the journal Human Genetics, adds fuel to the decade-long debate about whether so-called "gay genes" might exist.
The researchers examined a phenomenon called "X chromosome inactivation" in 97 mothers of gay sons and 103 mothers whose sons were not gay.
http://www.livescience.com/health/060224_gay_genes.html
A new study shows that gay men respond differently from straight men when exposed to a suspected sexual stimulus found in male sweat.
When homosexual men smelled the odor of male sweat—more specifically, a chemical in the male hormone testosterone—their brains responded similarly to those of women. The findings suggest that brain activity and sexual orientation are linked. It also supports an opinion held by most scientists, that people are born—not bred—gay.
http://news.nationalgeographic.com/news/2005/05/0510_050510_gayscent.html
Smelling a male pheromone prompts the same brain activity in homosexual men as it does in heterosexual women, a new study has found. It did not excite the sex-related region in the brains of heterosexual males, although an oestrogen-derived compound found in female urine did.
The testosterone-derived chemical AND is found in male sweat and is believed to be a pheromone. It activated the anterior hypothalamus and medial preoptic area of gay men and straight women alike. Researchers led by Ivanka Savic at the Karolinska University Hospital in Sweden believe this brain region integrates the hormonal and sensory cues used in guiding sexual behaviour.
http://www.newscientist.com/article/dn7358-pheromone-attracts-straight-women-and-gay-men.html
