Nature versus Nurture: Homosexuality's Link to Biology and Society

Biology 202, Spring 2005
Third Web Papers
On Serendip

Nature versus Nurture: Homosexuality's Link to Biology and Society

Sonya Safro

I first came across this article when a friend of mine and I were having a long conversation about homosexuality and biology. I had believed that there was an evolutionary objection to any genetic theories of homosexuality: animals are programmed to reproduce and that is their natural motive for having sex. However, my friend informed me about the penguins, and I began to think more about whether homosexuality is a trait that is inherited at birth, or whether sexual orientation is dependent on the environment one is brought up in. I wish to explore the "gay gene" theory, the debate over nature versus nurture, and the emotional, political, and social controversies about homosexuality.

In 1993 Dean Hamer, a scientist who works at the National Cancer Institute, wrote an article in the journal Science called "A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation.2 This controversial article explored homosexuality from a scientific perspective: it was not a choice, or a "form of psychological deviance," but more about biology and genetics. Politics hit the roof with this article. The gene debate and supporters of a biological cause for homosexuality are linked with being pro-gay, just as those who claim science has nothing to do with it may be targeted as homophobic. It's important to wonder: could researchers be taking a stance based on their own sexual orientation?

Hamer claimed to have found evidence for an unidentified gene on the X-chromosome that was passed from mother to son and had an influence on the child becoming gay. With research about gay brothers, Hamer and his colleagues assert that the Mothers' genetic skew correlates to their gay sons. Hamer is trying to discover a gene through the X-chromosome and find out how it controls the sexual orientation trait. On the other hand, this has been challenged by other scientists who believe that Hamer's evidence and research is too weak and broad. It appears as though many other factors may be influencing each of the mothers' sons, and that a more varied and repetitive research is needed.

This unidentified gene has also been found in fruit flies. However, the leap from flies to humans has caused many biologists and researchers to claim that homosexuality is resolutely embedded in genetics and biology. In other words, even if we cannot fully identify the gene at this moment, or completely understand how this is so, biology is the main factor. Finding same sex behavior and the unidentified gene in flies, as well as mice, sheep, and other animals is important because humans share the bulk of their DNA with these other species3.

A gay sheep study backs up the notion that biology has a lot to do with homosexuality. The hypothalamus is known to control sex hormone release as well as sexual behavior, has been found to have distinctive differentiation in the rams. The hypothalamus is twice as large in rams as in ewes, however in gay rams; it was the same size as the "straight" females. These differences in the hypothalamus in size are almost identical to the differences found in neuroscientist Simon LeVay's study of the brains of gay men. Sheep and humans are the only animals where males can physically express utterly gay sexual preferences. Also, the hypothalamus has an enzyme called aromatase, which converts testosterone into estrogen. This has a lot to do with the hormones that present during a fetus' development.

A very interesting debate regarding homosexuality is this "nature vs. nurture" argument. Thomas Schmidt, in "Straight & Narrow? Compassion and Clarity in the Homosexual Debate," takes a religious stance, and looks at homosexuality through something he calls the "multiple-variant model.4" This model is Schmidt's attempt to get rid of the biological theory that homosexuals were born that way, which he believes is not correct. This multiple-variant model associates many external, environmental factors with a person's sexual orientation. Social constructivism, early childhood environment, early trauma, and individual choice are the most critical factors Schmidt connects to homosexuality.

Schmidt argues that the way a parent fosters his or her child influences a child's eventual sexual preference. He gives many examples of external factors, such as a son who doesn't receive love from his father, thus always searches to fulfill this emptiness by engaging in relationships with other men. If a child, more specifically a boy, is teased all throughout his childhood by his peers and considered a "sissy," then he will relate more to the girls in his age group and become like one of them, ultimately even liking males.

Schmidt also talks about choices. Feminism, he claims, is a big influence on a female becoming attracted to someone of the same sex, as well as people considered to be counter-culture like. Basically, Schmidt believes that homosexuality is a choice, and furthermore a morally wrong one that is only perpetuated by people's decisions to act upon it. He ends his argument by suggesting Christian therapy to help stop homosexuality.

This argument gives of a religious fanatic vibe. While Schmidt makes some useful points about the need to replicate biological researches and evidence of its link to homosexuality, and while I do believe sexual orientation has lots to do with environmental factors, his message is biased and conservative: based on his religious upbringings, he has learned that homosexuality is a sin, and that gays choose to commit this "sin." Schmidt claims that no relevant or important research has been done to actually prove a genetic association to homosexuality, thus he dispels all notions of the likelihood. However, in truly understanding homosexuality and dealing with this highly controversial and emotional topic, I believe that people should be open and willing to all possibilities.

A friend of mine at Bryn Mawr College, who identifies herself as a lesbian, told me that she can't help being gay: "I knew since I was 10 that I liked girls. I tried to keep it a secret but I just couldn't hide it or change the way I was. It's not fun being gay, I know lots of people who wish they weren't." As I contemplated my friend's statement, I thought about how society is so devoted to and affected by the "gay gene" debate and the issue of homosexuality as either genetically influenced or environmentally caused.

Why indeed are researchers attempting to find a gene that proves once and for all that homosexuality is in fact not a choice but a hereditary feature? Could this lead to homosexuality being considered a flaw and something that may be "fixed?" Why can't we live in a world where it's simply okay for a person to be gay, or straight? So many theories have been given concerning love and the brain, such as love being simply a chemical reaction stimulated in the brain causing someone to feel that they are truly in love with another. However, the world is still full of romantics who will always believe that love is an amazing, unexplainable thing. Homosexuality, unlike love, is not regarded as natural or even unexplainable by many people.

So is homosexuality an instinct people are born with, or is it learned? Or both? I have come to learn more about biology and homosexuality, the current research that has been going on and that has been debated. I think research is important in understanding why we are who we are. It is pressing, however, to see that homosexuality is such a heated topic. It is scary to think that our last presidential election results actually had so much to do with gay rights. People are set in their beliefs, whether cultural or religious, and while environment of course plays a huge role in people becoming who they are, perhaps we need to look outside of just society's influence.

If we accept that homosexuality is indeed biologically inherited and not an option, then it appears that many people will have to accept this as unalterably and unchangeably part of that person. Homosexuals would have to be accepted, because then it would be clearly wrong to discriminate, as it goes for race and gender5. Still, there may be repercussions with the acceptance of the "gay gene" theory, such as continued discrimination by others now viewing homosexuality as a defect. Our society is a complex one, where science and biology has so much to do with facts, reality, and our further development as intelligent human beings in a civilized world. Yet, we continue to hold prejudices, set beliefs and views in a culture-driven humankind that still has a lot of learning, and a lot of "getting it less wrong."

1 http://www.jrn.columbia.edu/studentwork/cns/2002-06-10/591.asp Columbia news Science
2 Http://www.ps.org/wgbh/pages/frontline/shows/assault/genetics/ The "Gay Gene" Debate
3 Http://www.well.com/user/queerjhd/sxthegenedebate.htm The Gene Debate
4 Http://home.messiah.edu/~chase/h/articles/schmidt/ "Straight & Narrow? Compassion and Clarity in the Homosexual Debate
5 http://www.innerself.com/Relationships/accept_homosexuality.htm Accepting Homosexuality