A group of American scientists (northwestern University Chicago) conducted a survey of about 400 gay men having brothers with traditional sexual orientation. It turned out that there are certain genes that predispose to homosexual relations.
Team leader Michael Bailey is sure that the man may be gay or will stick to traditional relationships - depends mainly on the structure of two small sections of the male genome. Studies show that the structure of DNA determines sexual orientation men.
The study results were published at the conference of the American Association for the advancement of science in Chicago. During the examination by 409 people with a different sexual orientation, the scientists took blood samples for genetic analysis. For comparison, blood was taken from the brothers of volunteers. It was found that the DNA in the two groups were matched at 50%. Most differences were observed in the plots Xq28 and Xq8 - sex chromosomes.
Scientists suggest that the genetic factor determines the sexual orientation of a man on third. Otherwise, writes the Times, it depends on external factors.