“There have been a lot of different theories about why there should be any differences in sexual orientation,” Hamer said. “In the distant past, religious notions were used. Later on, Freud postulated that it was a deviation in normal development.”
Hamer also discussed the theory that homosexuality is the result of social learning, or learning from other people. Other theories suggest that differences exist between homosexuals and heterosexuals in certain regions of the brain and in the amount of testosterone and estrogen within the body.
Hamer investigated the biological explanations for this question. He has found circumstantial evidence to support his research. “[In a study on] identical twins, whose genetic makeup is the same, 60 percent of gay men also had a gay twin.” Studies of families have yielded interesting results. “More gay guys come from the mother side of the family,” Hamer said.
This discovery led Hamer and his research team to hypothesize that the sought-after genes would be found in the X-chromosome, which is inherited from the mother. Hamer has been able to distinguish, though not isolate, one gene that is commonly found in homosexuals. “[The occurrance of] this gene doesn’t mean that a person will be gay, [but] it tips the scales in one way or another,” he said.
Hamer has also repeatedly emphasized the role of the environment in determining behavior.
Assistant Professor of Psychology Sarah Turgeon believes Hamer’s research is of profound importance. “The one point I found the most striking was the problem of getting research in this area funded,” she said. “It’s a fascinating area of research with regard to the specific question of sexual orientation, but also with regard to behavioral genetics in general.”
Jason Cavatorta ’04 enjoyed the lecture. “He presented scientific arguments well to people who aren’t necessarily educated scientifically.”