Born That Way? Facts and Fiction
about Homosexuality

By A. Dean Byrd, Ph.D., MBA, MPH

Dr. Byrd gave this presentation at the recent FAIR conference held in Sandy, Utah.  FAIR is a Mormon apologetics organization.  To learn more about them and read other stimulating articles go to www.fairlds.org

In the world of the academy, homosexuality is an issue on which there is little genuine intellectual exchange these days. And it's this topic that FAIR has asked me to address. I should perhaps add to the introduction so that you can appreciate my perspective. You need to know that I am not much of an activist on this issue or any other issue. I direct a research organization, teach at the medical school, and manage to provide therapy for a unique population--men who are distressed by their unwanted homosexual attraction.

As I reflected on this patient population who I have treated for more than three decades, many of these men had religious backgrounds, although a substantial minority, perhaps as much as 40%, did not. For the single men who struggle with these unwanted attractions, the most frequent complaint was: "Gay relationships are not working for me. Would you help me explore my options?" For the men who were married, I frequently heard the following: "I love my family--my wife and children. I have these homosexual attractions, and I am only able to have a sexual relationship with my wife when I fantasize about having sex with a man. I have thought about becoming involved with a gay partner, but I want to honor my commitment to marriage and family. I really don't want the attractions. These homosexual feelings never really felt like a part of me or who I really am. Can you help me diminish the homosexual attractions and increase my sexual attractions for my wife?"

Many in the mental health professions would have me refuse to provide such psychological care to individuals even when such therapy is based on their request. They would have me say something like the following "a homosexual orientation is fixed and unmodifiable. I can only help you become more comfortable with your homosexual attractions."

There is a considerable body of ideologically inspired "scholarship" which leans toward the notion that homosexuality is so strongly compelled by biological factors that it is indelibly ingrained in a person's core identity, and is therefore not amenable to change. Many of these articles, though well-written, do not reflect good science. In fact, the social advocacy of the articles would suggest a greater reliance on politics than on the scientific method.

There are basically three studies that led activists to trumpet the notion that homosexuality is biologically determined. These studies were conducted by Simon LeVay, Dean Hamer, and the team of Michael Bailey and Richard Pillard. Perhaps a brief review of these studies would lay a good foundation for my lecture today.¹

At the time of his research, Simon LeVay was a biological scientist at the Salk Institute in San Diego. He conducted research on the brains of two groups of men: homosexual men and men who LeVay presumed were heterosexual. With a fairly small sample size (19 homosexual men and 16 presumed heterosexual men), LeVay conducted a post-mortem examination focusing on a particular cluster of cells in the hypothalamus known as the INAH-3. He reported that he had found "subtle but significant differences" between the brains of homosexual men and the heterosexual men. LeVay's research had a number of important limitations. He had very little information about the sexual histories of the research participants. Some of the subjects died of AIDS. Although there were differences between experimental and control groups, some presumed heterosexual men had small brain nuclei in the critical area, and some homosexual men had nuclei large enough to be within the normal heterosexual range. Activists proclaimed that the biological roots of homosexuality had been established. Listen to LeVay's interpretation of his research.

But it is important to stress several limitations of the study. First the observations were made on adults who had already been sexually active for a number of years. To make a real compelling case, one would have to show that these neuroanatomical differences existed early in life preferably at birth. Without such data, there is always at least the theoretical possibility that the structural differences are actually the result of differences in sexual behavior perhaps the "use it or lose it" principle. Furthermore, even if the differences in the hypothalamus rise before birth, they might still come about from a variety of causes, including genetic differences, differences in stress exposure, and many others. It is possible that the development of the INAH-3 (and perhaps other brain regions) represent a 'final common path' in the determination of sexual orientation, a path to which innumerable factors may contribute.²

Quoting LeVay,

Another limitation arises because most of the gay men whose brains I studied died of complications of AIDS. Although I am confident that the small size of INAH-3 in these men was not an effect of the disease, there is always the possibility that gay men who died of AIDS are not representative of the entire population of gay men... It will not be possible to settle this issue definitively until some method becomes available to measure the size of INAH-3 in living people who can be interviewed in detail about their sexuality.³

Further, LeVay summarized his research results in the following way:

It's important to stress what I didn't find. I did not prove that homosexuality was genetic, or find a genetic cause for being gay. I didn't show that gay men are born that way, the most common mistake people make in interpreting my work. Nor did I locate a gay center in the brain INAH-3 is less likely to be the sole gay nucleus of the brain than a part of a chain of nuclei engaged in men and women's sexual behavior...Since I looked at adult brains we don't know if the differences I found were there at birth, or if they appeared later.⁴

Commenting on the brain and sexual behavior, Dr. Mark Breedlove, a scientist as the University of California at Berkeley, demonstrated that sexual behavior can actually change brain structure. Referring to his research, Breedlove states, "These findings give us proof for what we theoretically know to be the case--that sexual experience can alter the structure of the brain, just as genes can alter it. It is possible that differences is sexual behavior cause (rather than are caused) by differences in the brain.⁵

Later, in his book Queer Science, LeVay offered additional clarification regarding biology and homosexuality:

Although there are significant differences between the attitudes of lesbians and gay men it is clear that both groups are far more inclined to consider their sexual orientation a biological given than is the general population....Should we take these assertions seriously? Not entirely, of course. No one even remembers being born, let alone being born gay or straight. When a gay man, for example, says he was born gay he generally means that he felt different from other boys at the earliest age he can remember. Sometimes the difference involved sexual feelings, but more commonly it involved some kind of gender nonconformist or sex atypical traits-disliking rough and tumble play for example, that were not explicitly sexual. These differences, which have been verified in a number of ways suggest that sexual orientation is influenced by factors operating very early in life, but these factors could still consist of environmental factors such as parental treatment in the early postnatal period.⁶

Finally, LeVay made an interesting observation about the emphasis on the biology of homosexuality. He noted, "...people who think that gays and lesbians are born that way are more likely to support gay rights."⁷

Bailey and Pillard Study

The next study was conducted by Michael Bailey and Richard Pillard who focused on identical twins, non-identical twins, non-adopted siblings and adopted siblings. In their sample, they had 56 sets of identical twins and 54 sets of non-identical twins. They found a 52% concordance rate for the identical twins which means that for every homosexual twin, the chances were about 50% that his twin would also be homosexual. For non-identical twins, the rate was about 22%, showing that about 1 in 5 twins who were homosexual had a homosexual brother also. For non-twin brothers, the concordance rate was 9.2%. Interesting enough, Bailey and Pillard found that the concordance rate in adopted brothers was 11.2%.

The most fascinating question, however, is that if there is something in the genetic code that makes an individual homosexual, why did not all of the identical twins become homosexual since they have the exact same genetic endowment? Neil Whitehead provided some comparative data on twin studies. The concordance rate for identical twins on measures of extroversion is 50%, religiosity is 50%, divorce is 52%, racial prejudice and bigotry is 58%. From the Bailey and Pillard study one has to conclude that environmental influences play a strong role in the development of homosexuality.⁸

Hamer Study

The third study, and perhaps the most sensationalized of the three studies since it emerged at the time of the controversy surrounding gays in the military during the Clinton era, was conducted by Hamer et al. Dean Hamer was a senior scientist at the National Cancer Institute. Hamer and his group attempted to link male homosexuality to a stretch of DNA located at the tip of the X chromosome, the chromosome that some men inherit from their mothers. In Hamer's study, he examined 40 pairs of non-identical gay brothers and asserted that 33 pairs--a number significantly higher than the 20 pairs that chance would dictate--had inherited the same X-linked genetic markers from their mothers.⁹

Criticism of Hamer's research came from a surprising source: George Risch, the scientist at Yale University School of Medicine who invented the method used by Hamer. Risch commented, "Hamer et al suggest that their results are consistent with X-linkage because maternal uncles have a higher rate of homosexual orientation than paternal uncles, and cousins related through a maternal aunt have a higher rate than other types of cousins. However, neither of these results are statistically significant."¹⁰

Commenting on his own research Hamer noted,

We knew genes were only part of the answer. We assumed the environment also played a role in sexual orientation, as it does in most, if not all behaviors... (Hamer & Copeland, 1994, p. 82). Homosexuality is not purely genetic...environment plays a role. There is not a single master gene that makes people gay...I don't think we will ever be able to predict who will be gay.¹¹

Citing the failure of his research, Hamer further wrote, "The pedigree failed to produce what we originally hope to find: simple Mendelian inheritance. In fact, we never found a single family in which homosexuality was distributed in the obvious pattern that Mendel observed in his pea plants."¹²

What is more intriguing is that when Hamer's study was replicated by Rice et al with research that was more robust, the genetic markers were found to be nonsignificant. Rice et al concluded:

"It is unclear why our results are so discrepant from Hamer's original study. Because our study was larger than that of Hamer et al's, we certainly had adequate power to detect a genetic effect as large as reported in that study. Nonetheless, our data do not support the presence of a gene of large effect influencing sexual orientation at position XQ 28 .¹³

When asked by Anastasia Toufexis, a Time reporter, whether his theory ruled out social and psychological influences, Hamer's response was "Absolutely not, ...from twin studies we already know that half or more of the variability in sexual orientation is not inherited. Our studies try to pinpoint the genetic factors, not to negate the psychosocial factors."¹⁴

In summarizing the biological studies on homosexuality Byne and Parsons offer the following summary, "Recent studies postulate biologic factors as the primary basis for sexual orientation. However, there is no evidence at present to substantiate a biologic theory, just as there is no evidence to support any singular psychosocial explanation. While all behavior must have an ultimate biologic substrate, the appeal of current biologic explanations for sexual orientation may derive more from a dissatisfaction with the current status of psychosocial explanations than from a substantiating body of experimental data. Critical review shows the evidence favoring a biologic theory to be lacking. In alternative model, temperamental and personality traits interact with the familial and social milieus as the individual's sexuality emerges. Because such traits may be heritable or developmentally influenced by hormones, the model predicts an apparent non-zero heritability for homosexuality without requiring that either genes or hormones directly influence sexual orientation per se."¹⁵

Independently, Friedman and Downey noted that credible evidence is lacking for a biological model of homosexuality.¹⁶ They conclude that "human sexual orientation is complex and diversely experienced and that a biopsychosocial model best fits the current state of knowledge in the field."¹⁷

So what does all of this mean about biology and the genesis of homosexuality? Critical reviews of the studies attempting to link biology and homosexuality, and subsequent acknowledgments by the researchers themselves, yield only one conclusion: biology alone is insufficient to explain the development of homosexuality. Any reputable scientist, regardless of which side of the political debate he or she embraces, when asked whether homosexuality is nature or nurture, must answer "yes." What is fascinating is that more than 50 % of the scientists who report research in this area are self-identified as gay or lesbian. This is disproportionate to the 2-3% (The Kinsey myth that 10% of the population is homosexual has been thoroughly discredited) which is the current estimate of the number of homosexual men and women in the population.

The developmental biologist form Brown University, Dr. Anne Fausto-Sterling, a self-identified lesbian, offers some interesting insight. Referring to the "born that way" argument, she states:

It provides a legal argument that is, at this moment, actually having some sway in court. For me, it's a very shaky place. It's bad science and bad politics. It seems to me that the way we consider homosexuality in our culture is an ethical and a moral question.

When asked about how much of her thinking about change in sexuality comes from her own life, Fausto-Sterling responded,

My interest in gender issues preceded my own life changes. When I first got involved in feminism, I was married. The gender issues did to me what they did to lots of women in the 1970s: they infuriated me. My poor husband, who was a very decent guy, tried as hard as he could to be sympathetic. But he was shut out of what I was doing. The women's movement opened up the feminine in a way that was new to me, and so my involvement made possible my becoming a lesbian. My ex and I are still friends. It is true I call myself as lesbian now because that is the life I am living, and I think it is something you should own up to. At the moment I am in a happy relationship and I don't ever imagine changing. Still, I don't think loving a man is unimaginable.¹⁸

So if biology is insufficient to explain the development of homosexual attraction, what does the research say about the developmental or environmental factors?

Come to Meridian tomorrow for Part II of “Born that Way? Facts and Fiction about Homosexuality”

Notes

¹ Simon LeVay, "A difference in hypothalamic structure between heterosexual and homosexual men," Science 253 (1991), 1034-1037; Dean Hamer, et. al., "A linkage between DNA markers on the X chromosome and male sexual orientation," Science 261 (July 1993), 321-326; J. Michael Bailey and Richard C. Pillard, "A genetic study of male sexual orientation," Archives of General Psychiatry 48 (1991), 1089-1096.

² Simon LeVay, Queer Science. (Cambridge, Massachusetts: MIT Press, 1996), 143-145.

³ Ibid.

⁴ D. Nimmons, "Sex and the brain," Discover (March 1994), 64-71.

⁵ M. Breedlove, "Sex on the brain," Nature 389 (1997), 801.

⁶ LeVay, Queer Science, 6.

⁷ Ibid., 282.

⁸ Neil Whitehead and B. Whitehead, My Genes Made Me Do It! A Scientific Look at Sexual Orientation (Lafayette, Louisiana: Huntington House Publishers, 1999).

⁹ Dean Hamer, et. al., "A linkage between DNA markers on the X chromosome and male sexual orientation."

¹⁰ N. Risch, E. Squires-Wheller, and B.J. Keen, "Male sexual orientation and genetic evidence," Nature 262 (1993), 2063-2064.

¹¹ N. Mitchell, "Genetics, sexuality, linked study says," Standard Examiner (April 30, 1995).

¹² Dean Hamer and P. Copeland, The Science of Desire (New York: Simon and Schuster, 1994), 104.

¹³ G.A. Rice, C. Anderson, N. Risch, and G. Ebers, "Male homosexuality: Absence of linkage to microsatellite markers at XQ28," Science 284 (1999), 665-667.

¹⁴ Anastasia Toufexis, "New evidence of a gay gene," Time 146 (November 13, 1995), 43.

¹⁵ W. Byne and B. Parsons, "Human sexual orientation: The biologic theories reapprised," Archives of General Psychiatry 50 (1993), 229.

¹⁶ R.C. Friedman, and J.I. Downey, "Neurobiology and sexual orientation: Current relationships," Journal of Neuropsychiatry 5 (1993), 131-153.

¹⁷ R.C. Friedman and J.I. Downey, Sexual Orientation and Psychoanalysis: Sexual Science and Clinical Practice (New York: Columbia University Press, 2002), 131.

¹⁸ C. Dreifus, "Exploring what makes us male or female," New York Times Science Section (January 2, 2001).