Monthly Archives: February 2015

Post1: Is Sexual Orientation Biologically Based?


Have you ever wondered whether sexual orientation is a biological construct or a product of one’s environment? I sure have! An I’m sure I’m not the only one

There are two perspectives through which we can explore this issue: First, biological (nature). Surprisingly, many studies have been conducted that compare the concordance of sexuality between identical and fraternal twins. According to the Free Dictionary concordance is  “the presence of a given trait in both members of a pair of twins” (Dictionary). In 1991, J. Michael Bailey and Richard Pillard conducted a study on identical and fraternal twins. Their findings were interesting! Whenever one identical twin was gay, the other was gay approximately 56% of the time (29/54), and that number decreases (22%) for fraternal twins and even further (11%) for adoptive brothers and for siblings who were not twins but biologically related (9.2%) (JAMA). 

Another study conducted about whether homosexuality is biologically dependent asserts that genes inform and influence one’s sexual orientation, specifically “at least two chromosomes affect whether a man is straight or gay” (the Guardian). Various biological elements play a role in forming a man’s sexual orientation such as DNA on chromosome 8 and a specific region of the X chromosome called xq28, which has evolutionary power. Evolutionary success–meaning a trait (in this case homosexuality)–was passed on because it helped one survive. Allegedly, researchers assert that the genes related to homosexuality in males were passed on through generations and for so long because it helped women who carried these genes be more fertile than other women without this gene. And since this gene is passed on only from mothers to sons, this gene has a similar natural occurrence. This study was also conducted by Michael Bailey at Northwestern University.

The findings of this study from Northwestern University only corroborates that of Dean Hamer, who in 1993, concluded that homosexuality was inherited after analyzing a sample of 100 gay men and found that 10% of the time the brothers of the men being analyzed were gay themselves. Hamer noticed that male cousins and uncles on the maternal side of the family had a higher probability of being gay and this caused him to observe and study the X chromosome because of the maternal link. He analyzed another sample in followup work and  discovered that 33 out of 40 homosexual male siblings (brothers) inherited the xq28 gene. (The Gay Gene: Assertions, Retractions and Controversy).

In 1957, Karen Hooker studied the relationship between homosexuality (sexual orientation), illness and psychological development in human beings. Hooker used people of two sexual orientations for this study: heterosexuals and homosexuals. Factors such as age, intelligence, level of education were taken into account and similar amongst the two groups of homosexuals and heterosexuals. The National Institute of Mental Health gave her a grant to conduct this experiment. Using the Make-A-Picture Test (MAPS), the Roscarch and the Thematic Apperception Test (TAT), she surveyed the two groups and received similar answers with little variation between each and as a result of her findings (main conclusion being that sexual orientation was not a product of one’s environment), the American Psychiatric Association decided to declare that homosexuality was not a psychological disorder. They removed it from the Diagnostic and Statistical Manual of Disorders in 1973.

Despite all of this evidence that suggests sexual orientation’s dependence on biology, we still must discuss the environmental influences on sexual orientation. Childhood Gender Nonconformity (CGN)  is a huge factor in determining homosexuality in adulthood, according to a great deal of studies. Daryl Bem was a psychologist and professor who studied Childhood Gender Nonconformity by analyzing a sample of 1000 lesbians and homosexual men with a control group of 500 heterosexual people and found that 63% of lesbians and homosexual men did not conform to gender normal activities (playing with barbie dolls for girls, playing with violent action figures or cars for boys), as compared to 10-15% of heterosexual men and women. Bem also came up with the Exotic Becomes Erotic Theory, which asserts that people have biological dispositions to enjoy the activities that they do. Some children will like things typical of their sex, and others will not. According to Bem’s theory, gender conforming children feel different from the opposite gender and gender non-conforming children feel different from children of their same gender. So when the child is near the different or “exotic” gender, then they become physiologically and eventually sexually aroused. As adults, they will view the gender that was most different to their own as sexually attractive (Exotic Becomes Erotic: a Developmental Study of Sexual Orientation).

Another study that asserts that environment affects sexual orientation was conducted by Danish epidemiologist Morten Frisch and statistician Anders Hviid. Their study challenges the popular conclusion to a Canadian one that asserted that the more older brothers a person had the more likely that person was to be gay. This new study conducted by Frisch and Hviid asserts that the more siblings a person has (brothers and sisters), the more likely that a person will marry heterosexually, not homosexually. The research strongly implies that there is a positive correlation between birthplace and homosexual orientation. A child who is raised or lives in an urban setting is more likely to marry homosexually and less likely to marry heterosexually. They also reported that children of divorce were less likely to marry heterosexually than children in non-divorced families. According to the study, for men, various things contributed to the likelihood that they would be gay: father’s absence, living shortly with parents, not knowing who their father is and living without father but with mother for too long. Homosexuality amongst women was more prevalent amongst ones who experienced abandonment periods by mother or whose mothers died during teenage years. (Childhood Family Correlates of Heterosexual and Homosexual Marriages: A National Cohort Study of Two Million Danes).

Now, I’m sure you’re asking, ‘which side does Jassy agree with?’ I have to agree with the environmental side because I see my view of how sexual orientation is developed reflected in the assertions of the scientists who argued about the environment cementing biological pre-dispositions to things that do not relate to sexual orientation, but gender assigning products (barbie dolls for girls, toy cars for boys) that later on help in developing a person’s views of the world, and of other people which I believe informs a person’s sexual identity as well as likes and dislikes in terms of what (and who) they find sexually attractive.

I very much agree with Bem’s Exotic to Erotic theory. I personally identify with it because as a child I did not always agree with the toys that were expected to be liked and played with by members of my gender, specifically barbies. I never liked barbie and found the entire idea of playing with dolls and playing dress up childish and a waste of time. Make up was ok, but toys were generally a childish enterprise that I wished to leave behind. And I have always identified as somewhat bisexual, so I believe Bem was onto something! Because of my personal identity and story I find it easy to believe that 63% of Bem’s sample of lesbians and gay men were non-conforming gender children. Back to the study! I agreed with his choice to use an observational/survey style of experimentation because it would help garner reliable evidence from the sample. I also like that Hviid and Frisch emphasized the positive correlation between geographical birthplace and sexual orientation. I like how they measured multiple environmental elements such as relationship to family members (not biological), as well as the probability that a person would marry homosexually or heterosexually in relation to that. I like how they analyzed the relationship between parents who were known and alive on the subject’s 18th birthday because I think it gives them a fair chance of assessing the strength of the relationship in the most ideal setting (parents alive, known whole life, still married) as opposed to the other extreme circumstance (parents divorced, absent due to abandonment or death).

I did not agree with the notion that sexual orientation is biologically dependent for a variety of reasons; mainly they had to do with how the researchers went about conducting their study. For example, I do not like the way that Katherine Hooker used the MAPS and TAT test on the homosexuals in her study because the requirement of either is for people to interpret a situation from a visual and based on their explanation that they dictate, their unconscious or conscious motives, desires, past experiences or concerns will be revealed. That’s great and all, but this might be a tedious process that is circuitous and indirect in solving something that does not have to be solved in the first place ( homosexuality). I guess I mean to say that either this study implies that homosexuality is a problem or that the subject will think this in their answers, which I do not think the objective of the study ought to be.

The main weakness that I attribute to the studies that favor the notion that sexual orientation is fostered by genetics ( or is biologically dependent) is self-selecting bias. The biological dependent studies all could have suffered from self-selecting bias which makes it more difficult to prove that genetics cause homosexuality  because gay siblings of homosexual twins are more likely to volunteer for studies (Schacter, Gilbert, Wegner “Psychology). Another criticism I have concerns Dean Hamer’s study. I do not find that the numbers that he came up with (10% of sample’s brothers’ were gay) because I do not find 10% to be a significant enough number to explore.

I hope this informed your perspective of whether sexual orientation depends more on nature (genetics) or nurture (environment). I can say that it surely helped me learn about myself!

Until Next Time,