Homosexual orientation by choice
This study , led by Alan Sanders at Chicago's North Shore University HealthSystem Research Institute, directly compared about 2,000 homosexual and heterosexual men in order to find genetic differences between them. They didn't find much. The researchers picked up some signal near several genes that are expressed in the brain. They also detected some genetic differences near the gene for the thyroid stimulating hormone receptor. This gene plays a role in Graves' disease , a thyroid autoimmune disorder that, according to a recent Danish study , occurs more often in gay men . These and other related findings, write Sanders and his colleagues, "point to a possible connection between thyroid function and sexual orientation in men." What can we take away from these modest results? The study, as the authors recognize, is fairly small as far as modern genetic studies go, and so its power to find genes linked to same-sex differences is li