The study analyzed 409 pairs of gay brothers, including sets of twins. (x)
NorthShore Research Institute has shown the strongest evidence yet that people are born gay. They conducted a study analyzing 409 pairs of gay brothers, including sets of twins.
“The study clearly links sexual orientation in men with two regions of the human genome that have been implicated before, one on the X chromosome and one on chromosome 8,” according to New Scientist.
New Scientist further detailed the experiment:
“Over the past five years, Sanders has collected blood and saliva samples from 409 pairs of gay brothers, including non-identical twins, from 384 families. This compares, for example, with 40 pairs of brothers recruited for Hamer’s study.
The team combed through the samples, looking at the locations of genetic markers called single nucleotide polymorphisms (SNPs) – differences of a single letter in the genetic code – and measuring the extent to which each of the SNPs were shared by the men in the study.
The only trait unequivocally shared by all 818 men was being gay. All other traits, such as hair colour, height and intelligence, varied by different degrees between each brothers in a pair and between all sets of brothers. Therefore, any SNPs consistently found in the same genetic locations across the group would most likely be associated with sexual orientation.
Only five SNPs stood out and of these, the ones most commonly shared were from the Xq28 and 8q12 regions on the X chromosome and chromosome 8 respectively. But this doesn’t mean the study found two “gay genes”. Both regions contain many genes, and the next step will be to home in on which ones might be contributing to sexual orientation.”
Study leader Alan Sanders of the NorthShore Research Institute in Evanston, Illinois says, “It erodes the notion that sexual orientation is a choice.”
Simon LeVay is a neuroscientist and writer who, in 1991, claimed to have found that a specific brain region, within the hypothalamus, is smaller in gay men. “This study knocks another nail into the coffin of the ‘chosen lifestyle’ theory of homosexuality,” he says. “Yes, we have a choice in life, to be ourselves or to conform to someone else’s idea of normality, but being straight, bisexual or gay, or none of these, is a central part of who we are, thanks in part to the DNA we were born with.”