Why are people gay

He adds that once the data are broken down into men and women, and into those who had only had same-sex partners versus those who had encounters across sexes, the number of people in each group becomes so small that the genetic linkages are very weak.

Dean Hamer, a retired geneticist in Haleiwa, Hawaii, who published some of the first studies on the genetics of sexual orientation, is disappointed with the study. Defining sexual orientation on the basis of a single same-sex encounter is not a useful way of categorizing people, he says, because many people who identify as heterosexual have experimented with a same-sex partner. Instead, he thinks the researchers have found genetic markers associated with openness to new experiences, which could explain the overlap between people who have had a homosexual partner and heterosexual people who have had many partners.

Zietsch says that risk-taking can explain only part of the statistical link between markers associated with same-sex encounters and those associated with number of partners. Hamer acknowledges that linking a complex behaviour to genetics is extremely difficult, but says he is glad the team is researching sexual orientation.

Zietsch, B. Nature Hum. Article Google Scholar. Ganna, A. Science , eaat PubMed Article Google Scholar. Download references. Article 10 NOV News 05 NOV News 04 NOV Research Highlight 03 NOV News 09 SEP Article 03 NOV In certain populations, female Japanese macaques will sometimes choose other females as sexual partners despite the presence of sexually motivated male mates. Female Japanese macaques will even compete intersexually with males for exclusive access to female sexual partners.

Specifically, people who believe sexual orientation is biological are more likely to favor equal rights for sexual minorities. When Atlantic contributor Chandler Burr proposed in his book, A Separate Creation , that people are born gay, Southern Baptists called to boycott Disney films and parks in protest against the publisher, Disney subsidiary Hyperion.

As the report authors explain:. Male fetuses carry male-specific proteins on their Y chromosome, called H-Y antigens. These antibodies bind to the H-Y antigens and prevent them from functioning. Blanchard believes that this phenomenon grows stronger with each boy a woman bears. Michael Bailey, a N orthwestern University psychologist with experience in genetics, told Science News. Bailey was not a part of this study.

Those hundreds of thousands of participants were found within two huge genetic databases: the home DNA testing company 23andMe, t he UK Biobank, as well as from three smaller studies.

Volunteers answered questions about how many sexual partners they have had, and what kinds of sex they had had. The researchers' analysis identified five genes which are clearly connected with same-sex sexual attraction. While the variations in these genes are not enough to raise a rainbow flag and label anyone as unquestionably gay, the researchers say these biological variants may at the very least partly influence sexual behavior. One was discovered in a chain of DNA which includes several genes related to the sense of smell; another one of the genes is related to male pattern baldness, which the authors said could suggest that sex hormone regulation may somehow be involved.

What does he mean by "environmental"?