Chapter Three Gay Brains and Gay Genes
Those advocating for homosexuality often misused the small number of studies that have been conducted which have shown a possible biological basis for homosexuality. This misuse actually began with the researchers themselves. The misuse is often with the intention of achieving a political objective. After having their research results published in the highly-respected journal, Science, both LeVay and Hamer went on to write books. The use and misuse of this research for a biological basis for homosexuality has come with mixed results. In finding a homosexual person it is hoped that the treatment of such individuals by others will be more favorable, and even gaining specific legal rights for homosexuals. Yet there is also the risk for greater unfavorable treatment, with possible attempts for the prevention of becoming a homosexual. The search for a biological basis to homosexuality first began in Germany during the 1860s.
For well over a century homosexualists have dreamed that the invention of the homosexual as a person would ultimately detoxicate homosexual behavior and win it a place of equality alongside heterosexual behavior. (De Ceeo,Confusing the Actor With the Act: Muddled Notions About Homosexuality, p. 411)
The biological claims of gay brains and genes, while power-charged interventions in the current cultural and political debates of difference, are by no means historically innovatory, as social historians of sexuality have long recognized (Weeks 1981). The claims instead resurrect the essentialist thesis advanced by politically engaged gay men and argued intermittently since the mid-nineteenth century to secure political and culture space for homosexuality. In a context of widespread political moves within the U.S. to deny homosexuals their constitutional rights, this oppositional discourse, with its twin location in the neurosciences and in molecular genetics, seeks to ground the claim for civil rights in the body. (Rose, Gay Brains, Gay Genes and Feminist Science Theory in Weeks, and Holland editors. Sexual Cultures Communities, Values, and Intimacy, p.54)
As this collection of papers has shown, the search for purely biological determines of sexual preference is fraught with short-comings. It conflates biological sex with gender and gender with sexuality, it reduces a given sexual preference to specific behaviors and further reduces those behaviors to biological processes, and it accepts and reinforces society’s whimsical moral judgments, categories, and proscriptions regarding sexuality. It is no wonder, then, that in spite of the zeal shown by researchers and the availability of sophisticated equipment and methodology over the past decade, the search for biological markers of sexual preference has failed to produce any conclusive evidence. (Parker and De Cecco, Sexual Expression: A Global Perspective, p. 427-428 in Sex, Cells, and Same-Sex Desire, edited by De Cecco and Parker)
As noted before the biological basis for homosexuality may be historically traced to the 19th century in Germany when homosexuals themselves begin advocating for legal rights. Up until this time homosexuality was as seen what one did, and it was a sin and a crime. Now it would also begin to have a medical and scientific connotation, there could now be a homosexual person. Yet in over 130 years there has not been found one homosexual person. Today many of those who practice homosexuality self-identify as homosexuals and have created and organized based these sexual acts.
The modern western concept of the homosexual is, according to some historians, primarily a creation of late nineteenth-century medical-science discourses. In the context of elaborating systems of classification and descriptions of different sexualities, as part of a quest to uncover the truth about human nature, the homosexual is said to have stepped forward as a distinct human type with his/her own mental and physical nature. (Seidman. Embattled Eros, p.146)
The second and related assumption of these research reports was that homosexuality, as a biological given, existed as the antithesis of heterosexuality. Over the past two decades, however, gay and lesbian scholarship has documented the fact that the notion that individuals exist as two distinct species, one exclusively heterosexual, the other exclusively homosexual, is of fairly recent origin, born in the eighteenth and nineteenth centuries and institutionalized in 19th century medicine (Foucault, 1976; Weeks 1991; Trumbach, 1991). In several historical periods and in many cultures, past and present, no such antithesis has existed. Almost anyone who engaged in homosexual practice was believed to be capable also of heterosexual practice. Nor was it thought that homosexual practice, especially in youth, in any way precluded adult heterosexuality (e.g., Dover, 1978; Herdt, 1981; Blackwood, 1985). (De Cecco and Parker, The Biology of Homosexuality: Sexual Orientation or Sexual Preference? p. 11 in Sex, Cells, and Same-Sex Desire: The Biology of Sexual Preference edited by John P. De Cecco, PhD and David Allen Parker, MA.)
Modern medicine and science has only added to the confusion. The discussion of homosexuality continues to be comprised of a seemingly endless philosophical battle between conflicting ideologies of essentialism and social constructionism. The best possible summary of this philosophical battle of ideologies may be stated in the following statements. Who one is, a homosexual, or What one does, homosexuality. The strongest evidence and support is for homosexuality, what one does. Those advocating for homosexuality have created these conflicting ideologies of essentialism and social constructionism.
The category of homosexuality carries a definition of the essential nature itself. As individuals are inserted into this discursive framework through the growing authority of medicine, science, psychiatry, and law, individuals who have same-sex longings are defines as unique, abnormal human type: the homosexual. (Seidman. Embattled Eros, 147)
In the early 1990s a small number of scientific studies reporting to find a biological basis for a homosexual person were published. The use of and response to these reports were a surprise to many people. The essentialism side temporally began to hold sway over those who hold to social constructionism. The strongest criticism to these published studies are among others who also advocate for homosexuality, but do so from a social constructionism perspective.
To no small extent, the amplification of the twin gay brains and gay genes these has produced not simply by media misrepresenting science - as science commonly claims - but directly through the language and activities of the scientists themselves. This process has worked its way through a mixture of press releases, titles and public comment. . . But most of all, neither LeVay nor Hammer reflect on the category homosexual for both it is fixed as, say, brown eyes. LeVay in particular has a very simple-minded view of sexuality. Thus, he reflects in passing that heterosexual copulation is so simple, one hardly needs brain to do it (LeVay, 1993, p.47). Thus, it is not the media which biologises the category but the gay scientist themselves. (Rose, Gay Brains, Gay Genes and Feminist Science Theory in Weeks, and Holland editors. Sexual Cultures Communities, Values, and Intimacy, p.62-63)
The argument for homosexual immutability betrays a misreading of the scientific research itself. Nothing in any of these studies can fully support the idea that homosexuality is biologically immutable; each study leaves open the possibility that homosexuality is the result of a combination of biological and environmental factors, and several suggest that homosexuality may be tied to a predisposition in temperament that could manifest itself in a number of ways. All, agree that biological, social, and psychological factors interact to produce and change the signs of homosexuality. Furthermore, these studies cannot comment effectively on the frequency of homosexuality in the general population. (Terry, An American Obsession p.394)
In studies like these, a type of circulating reasoning often follows the delineation of the subject population: scientific research on homosexuality does not begin with random populations, but rather with groups of people who are defined as homosexual to begin with (by themselves, by scientist, or by both); then, researchers search for a biological (or social) marker common to the group (whether it be a gene a portion of the brain, or an overwhelming mother); finally, if such a marker is found, homosexuality is redefined by the presence of the marker itself. In a curious way, than, each study can be said to reinvent its own object. (Kenen, Who Counts When You’re Counting Homosexuals? Hormones and Homosexuality in Mid-Twentieth-Century America, p. 197 in Science and Homosexualities edited by Vernon A. Rosario)
Science cannot yet produce unequivocal answers to many of the questions that exercise politicians or excite moral debate. Research points to a manifestations of homosexuality being the outcome of ongoing interplay between a multiplicity of factors, some genetic, some environmental, the latter including the environment of the developing fetus as well as upbringing, family situation, social and legal climate, and culturally permitted outlets. It appears likely that the direction of sexual impulses in some individuals is largely a matter of innate, biological disposition, whereas in others the kind of sexual experiences to which they are exposed is more influential. There appears to be in many contrasting societies a hard core of homosexuals whose behavior is not altered by even the most draconian sanctions. The causes may well be different for homosexuals whose general behavior conforms to what is expected of their sex than those who do not comply with gender expectations in either social behavior or heterosexual performance. (West, Supposed Origins of Homosexuality and Implications for Social Control, p. 312 in. Sociolegal Control of Homosexuality A Multi-Nation Comparison, editors West, and Green)
In summary, with the exception of the few clear biological anomalies that result in cross-gender structural anomalies, it is impossible to disentangle the biological and psychological contributions to the behavioral differences that constitute sexual orientation. As Breedlove (1994) affirmed, biology and psychology are simply disciplines that offer different means of describing the same phenomena. (Baumrind, Diana. Commentary on Sexual Orientation: Research and Social Policy Implications, p.132)
Biologic theories can account for the feelings that motivate behaviors; the behaviors themselves will be strongly determined by the environmental factors-in the case of sexual orientation such factors as available opportunities and social and legal sanctions. (McConaghy, Biologic Theories of Sexual Orientation, p.431)
Certainly, as biological organisms, any and all of our behaviors must have biological correlates, but that does not mean that those correlates determine our behavior. In fact one of the maxims of scientific research is ,correlation is not causation. We are more then, biological organisms; we are creatures shaped by experience, emotion, time, and circumstance, and in turn, we re-shape ourselves for our needs and our goals. Sexuality can be reduced to neither a purely biological state nor a purely psychosocial one. Any plausible explanation of sexual expression would have to include all its components. (Parker and De Cecco, Sexual Expression: A Global Perspective, p. 428 in Sex, Cells, and Same-Sex Desire, edited by De Cecco and Parker)
It remains difficult, on scientific grounds, to avoid the conclusion that the uniquely human phenomenon of sexual orientation is a consequence of a multifactorial developmental process in which biological factors play a part, but in which psychological factors remain crucially important. If so, the moral and political issues must be resolved on other grounds. (Bancroft, Homosexual Orientation The search for a biological basis, p.439)
In the literature that discusses a biological basis for homosexuality usually there are three broad categories for those biological causes of homosexuality, hormonal, within the brain, and genes. They are then broken down into subcategories with many more details then what is really needed. In the hormonal category, they are divided into prenatal, before birth, and postnatal, after birth. The hormones are usually those that deal with gender, i.e. they effect masculinity and feminity, or hormones that interact with sexual functioning. The hormones are testosterone, estrogen, and LH (luteinizing hormone). In the brain the area studied is the hypothalamus, and there are four regions of the anterior hypothalamus which is discussed (INAH 1, 2, 3, 4). When doing gene studies, they are divided into two categories, indirect where twins and families are studied; and direct, where specific genes themselves are studied.
There are three major types of biological models of same-gender orientation (Byne and Stein 1997). Formative experience models assume biology shapes the organizing and interpretation of life experiences, including sexual desire. Direct effects models hold that factors like genetic predisposition or prenatal hormones produce brain circuits determinative of sexual orientation. And indirect models suggest that biological factors like temperament, not directly related to sexuality, indirectly shapes sexual orientation. Direct effect models involving behavioral genetics, hormonal influences, and regional brain studies have gained particular prominence in the last decade.
Whatever their intrinsic merits, searches for a biological bases for homosexuality have been plagued by the difficulty of finding reliable and valid means to identify clear groups differentiated by sexual orientation. (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 53)
A more detailed look at studies by LeVay, a gay brain, and Hammer, a gay gene follows. These individuals and their studies were the ones that seem to generate the most excitement in the popular press. Upon their release in the journal, Science, they subsequently became the headlines in the popular media with the resulting politicizing and propagandizing quickly following. Who are these scientists, and what are their qualifications, will tell us much about their intent in publishing their studies. What is often not discussed is the loss of scientific objectivity with the use of these studies for a possible biological basis for homosexuality in attempting to gain popular support and even political gain for homosexuality.
The two scientists LeVay and Hamer, who conducted these studies of a gay brain and a gay gene self-identify as a homosexuals. These two studies have never been replicated, and subsequent studies have shown results that contradict the original studies. The popular media has given much more press to the original gay brain and gay gene studies, but all of the studies have been reported in scientific literature. Both LeVay and Hamer conducted their studies in areas that they normally did not study. They were both acknowledged scientists in their fields, and their research was conducted at well renowned facilities, which helped to lend credit ability to their studies. Both LeVay and Hamer went on to write books after publishing their research findings advocating biological causations for homosexuality. With this all said and done, though LeVay and Hamer were passionate researchers, their research was less then impartial. LeVay conducted his gay brain research and study after his male lover died from complications of AIDS. Hammer after seeing many of his friends dying from Kaposis sarcoma decided to look into a possible genetic predisposition for gay men to get this rare and now predominantly AIDS-related cancer.
The origins and determinants of sexual orientation, both heterosexual and homosexual, pose unanswered questions of genuine scientific interest. But the scientific enquiry they have engendered reveals a long history of distortion by moral and political considerations. This is an area, par excellence, where scientific objectivity has little chance of survival. (Bankcroft, Homosexual Orientation The search for a biological basis. p.437)
Under the sort of scientific-technical approach favored by a Hamer or LeVay, information that does not fit existing theories and preferred modes of research in effects falls into limbo; it is made to disappear, as though it had never existed. (Clausen, Beyond Gay or Straight, p.127)
In studies like these, a type of circulating reasoning often follows the delinearation of the subject population: scientific research on homosexuality does not begin with random populations, but rather with groups of people who are defined as homosexual to begin with (by themselves, by scientist, or by both); then, researchers search for a biological (or social) marker common to the group (whether it be a gene a portion of the brain, or an overwhelming mother); finally, if such a marker is found, homosexuality is redefined by the presence of the marker itself. In a curious way, than each study can be said to reinvent its own object. (Kenen, Hormones and Homosexuality in Mid-Twentieth-Century America, Rosario, Vernon A. editor. Science and Homosexualities, p.197)
To be specific, it is necessary to investigate the biological research to determine exactly what it has to say about homosexuality. The studies of LeVay and Hamer, for example, which are often associated with the biological argument, were limited in scope and never have been satisfactorily replicated (Crewdson 1995). In addition, both studies used only male subjects; therefore, the data only support the biological argument as applied to male homosexuals. Finally both LeVay’s and Hamer’s studies draw on a wide variety of scientific studies that contain varying theories of male homosexuality, many of which conceptualize male homosexuality as pathology. (Brookey, Reinventing the Male Homosexual: The Rhetoric and Power of the Gay Gene, p. 7)
LeVay’s Gay Brain"
Science, one of the leading journals in the scientific field published in 1991 an article by Simon LeVay, A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men. This is the article and study that became the basis for the gay brain headlines. But it was not without controversy for both the journal and its author. LeVay was a neurobiologist who performed his research at the Salk Institute for Biological Studies in CA. His previous research had been on a distinctly different region of the brain known as the visual cortex. LeVay himself said on a The Phil Donahue show, (Genetically Gay: Born Gay or Become Gay, January 3, 1992) that his study was not entirely a dispassionate scientific endeavor. He conducted his research and study after his male lover died from complications of AIDS. In a sense LeVay was personally outing himself with the publication of his research and study.
LeVay simply joined other scientist in the not uncommon error of overlooking the limitations of his research to push for an unjustified conclusion. The case is a classic example of the search for some kind of physical difference to account biologically for phenomena that results from complex, multilayered sets of processes clearly influenced if not structured by macro- and microculture. (Spanier, Biological Determinism and Homosexuality. p. 44 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
LeVay has said that the motive for his research was to honor the nature of his relationship with his lover, Richard Hersey, who died of AIDS. (Murphy, Gay Science The Ethics of Sexual Orientation Research, p.25)
I do not fault Simon LeVay for trying to make a contribution to understanding sexuality and for changing his life dramatically from quiet scientist to public activist, revealing his long relationship with a doctor who died in 1990 from AIDS. (Spanier, Biological Determinism and Homosexuality. p. 43 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
The claims were immediately contentious both within and without science. Despite LeVay’s evident cultural capital which would make him more publishable than an outsider, it is questionable whether Science would have published an article of similar methological vulnerabilty had it focused on anything less charged than homosexuality. The sample was small, and AIDS commonly produces severe neurological consequences. There were no normal controls, and he sought to measure a brain region whose boundaries are notoriously difficult to define. His findings have not been replicated. (Rose, Gay Brains, Gay Genes and Feminist Science Theory” in Weeks and Holland editors. Sexual Cultures Communities, Values, and Intimacy. p. 59)
Simon LeVay’s research is another useful example of the dynamic of science and politics, in this case, politics supporting gay rights. LeVay was a neurobiologist at the Salk Institute in California (a highly reputable research institute) when he published an article in Science that put another twist on the "nature vs. nurture" debate. For at least a hundred years, claims have been made that homosexuals are biologically different from heterosexuals, so the claim is not new. What is new is the context in which the claim is made, a context in which a combination of gay and lesbian liberation movements and the AIDS crisis have forced greater acceptance of homosexual activity to a limited but nonetheless considerable degree. Of great significance here is the fact that LeVay is an openly gay, scientist, and that this information was revealed in an issue of Science subsequent to the article’s publication. (LeVay may well be the first scientist to be identified as gay in Science (Barinaga).) Along with many other supporters of gay rights, he sees the "scientific" evidence of a biological determinant of gayness as a crucial factor in preventing psychiatrists, lawmakers, and citizens in general from slipping back into-believing that homosexuality is a mental illness - or that it is criminal or immoral. (Spanier, Biological Determinism and Homosexuality. p. 36 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
LeVay’s scientific article and comments made in interviews make it very clear that the framework within which LeVay conceptualizes the causes of sexual orientation derives from a belief that specific parts of our brains control our behaviors, including those related to sex. The reification of complete, dynamic processes (such as intelligence) and the imputation of causality to physical parts of the body (such as the cerebral cortex or sets of genes) are common errors in the long history of biological determinist claims (Hubbard; Lewontin, Rose, and Kamin). To support such claims, much evidence is ignored, such as a functioning medical student who has only 10% of his cerebral cortex (Fausto-Sterling, chap. 2). (Spanier, Biological Determinism and Homosexuality. p. 39-40 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
LeVay’s study was initially rejected by the in-house reviewers at Science (LeVay, personal communication). Although Science rarely allows resubmission of manuscripts, an exception was made in this case. Because Science refuses to comment on this exceptional treatment, one can only speculate as to why their initial decision had been to reject the manuscript even before sending it out for peer review. Perhaps the reason for this is that paper did not meet the minimal standards to which even animal research in this area is held. This paper had a single author who did all of the tissue processing as well as all of the anatomical measurements and statistical tests. Even in animal work, the standard has been that all measurements are made not only blindly but also by more than one investigator. Certainly, the editors at Science should have been more cautious and required that a co-investigator repeat and verify LeVay’s measurements prior to publication of a study that was sure to be of great interest to the general public as well as to the scientific community. While LeVay has stated that there was no suitable co-investigator in his laboratory at the time he conducted this study (quoted in Marshall, 1992), there is no lack of qualified anatomists who would have been (and still would be) more than willing to check his measurements. (Byne, Science and Belief: Psychobiological Research on Sexual Orientation, p.334 in Sex, Cells and Same-Sex Desire, editors John P. De Cecco PhD and Michael G. Shively, MA)
In August of 1991 Science magazine published an article by LeVay entitled A Difference in Hypothalamic Structure between Heterosexual and Homosexual Men." The article claims that one of four particular groups of cells (called INAH 1, 2, 3, and 4 for the interstitial nuclei of the anterior hypothalamus) of the brain was twice as large in heterosexual men as in homosexual men or in women (no sexual orientation specified). From that observation, LeVay concludes in the high-lighted abstract that precedes the paper: "This finding indicates that INAH  is dimorphic with sexual orientation, at least in men, and suggests that sexual orientation has a biological substrate" (1034). (Spanier, Biological Determinism and Homosexuality. p. 37 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
LeVay’s research was the study of the brain tissue from 41 subjects that was obtained from routine autopsies of those who died at 7 metropolitan hospitals in New York and California. 19 of the subjects were homosexual men who died of complications from AIDS (1 was a bisexual). There were an additional 16 male subjects which were presumed to be heterosexual, of these, 6 died from AIDS and 10 from other causes. The final 6 subjects were women presumed to be heterosexual, of these 1 died from AIDS and 5 from other causes. What LeVay did was to measure the size of the INAH3 portion of the hypothalamus. His research and results were published in the Science article.
The discovery that a nucleus differs in size between heterosexual and homosexual men illustrates that sexual orientation in humans is amenable to study at the biological level, and this discovery opens the door to the studies of neurotransmitters or receptors that might be involved in regulating this aspect of personality. Further interpretation of the results of this study must be considered speculative. In particular, the results do not allow one to decide if the size of INAH 3 in an individual is the cause or consequence of the individual sexual orientation, or if the size of INAH 3 and sexual orientation covary under the influence of some third, unidentified variable. (LeVay, A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men, p. 1036)
It had also been determined that human hypothalamus was sexually dimorphic, which is to say, certain clusters of cells in the gland were dependably larger in men than in women. Hypothesizing that perhaps the cells were dimorphic for sexual orientation rather than sex, LeVay found in his forty-one brains that clusters of INAH3 cells in the hypothalamus glands of men who had apparently been gay were consistently smaller than those men who had apparently been heterosexual. The brains of the women, all who were (almost groundlessly) presumed to be heterosexual, had similarly smaller INAH clusters. LeVay ultimately decided that the size of the INAH3 clusters were determined by sexual object choice, and not by sex itself. So, brains that were attracted to women were had large INAH3 concentrations, brains that were attracted to men had smaller ones. (Archer, The End of Gay and the death of heterosexuality, p.132)
LeVay’s originality lies in proposing that the larger size of INAH 2 and INAH 3 correlates with sexual orientation - "desire for women" - rather than with gender - maleness - as the previous studies had done. He summarizes and postulates at the same time, "Thus, these two nuclei could be involved in the generation of male- typical sexual behavior" (1035), asserting that brain structures may cause certain behaviors. (Spanier, Biological Determinism and Homosexuality. p. 37 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
Not only does LeVay’s thesis propose that the difference in size is due not to gender difference as previously claimed but to sexual orientation difference, but he also asserts that the size difference proves a biological basis for sexual orientation. The qualification, "at least in men" (1034), immediately pinpoints a primary problem with LeVay’s study as he conceives it. To test his theory, he should be comparing large enough numbers in (at least) four categories: heterosexual men, homosexual men, heterosexual women, and homosexual women. Note, too, that while Laura Allen’s work found sexual dimorphism for both INAH 2 and 3, LeVay points only to INAH 3 in his conclusion. What do we make of this? A close analysis and critique reveals even more serious problems with the construction of the study leading to LeVay’s claims. (Spanier, Biological Determinism and Homosexuality. p. 37 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
This study by LeVay was heralded by those advocating for homosexuality as proof for the biological basis and innateness of homosexuality. Those who oppose homosexuality have raised questions concerning LeVay’s study. But of most interest is the response to LeVay’s study by those advocating for homosexuality. Numerous articles and books have been written of LeVay’s study of a gay brain.
The study, as LeVay himself admits, has several problems: a small sample group, great variation in an individual nucleus size, and possibly skewed results because all of the gay men had AIDS (although LeVay found no significant difference in the volume of INAH3 between the heterosexual men who died of AIDS and those who died of other causes). As of this writing, Levay’s findings have yet to be replicated by other researchers. (Burr, Homosexuality and Biology in Silker, Homosexuality in the Church, p.124)
The reader is entitled to be skeptical if not confused by these findings. There is either lack of consistency or of replication. There are methodological problems. Numbers are inevitably small, and most studies homosexual subjects have died of AIDS; the possibility that such structural changes could be the consequence of disease, such as AIDS, remains. But even if these findings are substantiated, and specific areas of the hypothalamus or elsewhere are found to be linked to sexual orientation, it is difficult to imagine what the nature of such link would be. It is certainly unlikely that there is any direct relationship between structure of a specific area of the brain and sexual orientation per se. (Bancroft, Homosexual Orientation The search for a biological basis. p.438)
A second problem is that to date, there have been no replications of LeVay’s finding; Byne (1994) reports that Manfred Gahr at the Max Planck Institute has tried unsuccessfully to replicate LeVay’s findings. Moreover, the interstitial nuclei in the anterior hypothalamus vary in size, in part in relation to seasonal factors, suggesting that these structures are not so immutable as LeVay’s research appears to assume. More than three dozen studies have failed to confirm LeVay’s (1991) claim that the corpus callosum is larger in male homosexuals than in heterosexual men. (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 82)
There have been other various studies that conflict each other, and LeVay’s specific research has not been replicated. Common criticisms of LeVay’s research are with methodological shortcomings. First is the small sample size, there were only 41 samples of brain tissues. There are many questions about the role of AIDS, which LeVay himself acknowledges. But the one area of his study that has resulted in the most criticism is how LeVay determined the sexual orientation of the subjects. This determination was after the fact, without any input by the subjects themselves. They had died. In most studies and research determination of sexual orientation or homosexuality is by self-proclamation of the participants themselves.
Second, questions have been raised about the fashion in which LeVay determined the orientation of the persons whose brains he was dissecting after death. Nineteen of the men were assigned the designation homosexual based on it being noted in the medical charts by their doctors; the remaining 16 men were presumed to be heterosexual on the basis that their sexual orientation was not mentioned in their charts. This leads us to suspect LeVay did not know for sure whether the brains of nearly half of the people he was studying were from homosexual or heterosexual persons. Further-more, all of the homosexual men and 6 of the presumed 16 heterosexual men died of AIDS. (Jones & Yarhouse, Homosexuality The Use of Scientific Research in the Church’s Moral Debate, p. 70)
LeVay himself has also noted that one subject who was listed as bisexual on his medical charts was lumped in with the homosexual subjects.
Medical records were his only source of information as to the sexuality of his subjects. While the charts of those who died from other causes than AIDS failed to specify sexual orientation, he assumed that, based on statistical probability, not more than one or two were likely to have been gay, and so felt justified in using them to represent the heterosexual male and female brain. (Clausen, Beyond Gay or Straight: Understanding Sexual Orientation, p. 106-107)
Vance and others have been struck by the contrast between the care with which LeVay measured his brain samples and the sloppiness of his assumptions concerning his subject’s sexuality. He had no idea how hospital workers arrived at the conclusion that the AIDS patients for whom they recorded a sexual orientation were indeed gay. Given what is known of human sexual diversity, it seems safe to assume that LeVay’s simple labels covered a wide range of specific desires and behaviors. Those subjects who did not die of AIDS were simply assumed, in the absence of evidence to the contrary, to be heterosexual- a peculiarly heterosexist assumption for a gay male researcher to make. (Clausen, Beyond Gay or Straight: Understanding Sexual Orientation, p. 109)
Problems he didn’t pay much attention to include the presumption of sexual identity in corpses that were doing no talking for themselves. If an AIDS patient had denied any homosexual activity to doctors before his death, his brain was labeled heterosexual. The presumption of heterosexuality among the women, as well, as among the men who died of cause other than AIDS, was based primarily, according to a note, on that misinterpreted Kinsey 10 percent. Chances were, LeVay said, these people were straight. (Archer, The End of Gay and the death of heterosexuality, p.133)
There is also a large and common critical basis of many scientific studies looking for biological causes this is taking animal research and applying it towards humans. As noted before same-sex physical activity and behavior is seen in animals, but not a homosexual animal. Research has been done trying to understand the mechanics of this same-sex erotic activity, what are the biological underpinnings. There are many studies using sheep and rats. Some of these studies in rats have located in the rat’s brain a location that regulates sexual physical behavior, the SDN-POA. So this area is thought to be similar to the portion of the human hypothalamus, INAH3. But first, different studies have found different portions of the hypothalamus to regulate sexual behavior. Remember there are 4 parts to the anterior hypothalamus. LeVay studied the INAH3 section of the hypothalamus. Others have criticized LeVay for trying to connect the rat’s brain, (SDN-POA) and the part it plays in sexual activity to the human’s INAH3 portion of the hypothalamus. Kauth’s criticism in his book is particularly pointed and direct.
Conceptually, LeVay’s finding could present a problem. LeVay asserted that the INAH3 functions much like the SDN-POA does in rats; the SDN-POA regulates sexual behavior but is not known to control sexual desire. The ability to perform certain sexual behaviors is not equivalent to sexual desire. LeVay confuses sexual orientation and sexual behavior. As motivated human behavior, erotic feelings are more complex than reflexively thrusting a penis into an opening or presenting one’s backside to be penetrated. Yet, by comparing the human INAH3 to the rat’s SDN-POA, LeVay emphasizes the importance of sexual behavior over sexual feelings and implies that mechanical behavior is the sine qua non of human sexuality. In actuality, the mechanics of sexual behavior -mounting, thrusting, rubbing, fondling, kissing, licking, and sucking -differ little across individuals of various erotic interests. Only the sex of the desired partner varies. Therefore, it is unlikely that the human INAH3 is functionally similar to the rat SDN-POA. LeVay’s premise is faulty, and his conclusions are suspect. His findings could easily reflect the different environmental experiences of his subjects rather than reveal anything about sexual orientation. No meaningful conclusions can be drawn from LeVay’s study. (Kauth, True Nature A Theory of Sexual Attraction, p.126-127)
The deterministic view of the brain’s relation to behavior also often assumes that brain structures influence behavior in a one-way, cause-and-effect direction, an assumption utilized throughout LeVay’s article until the author discusses some of the limitations of his study. At that point he notes that his results do not determine whether different cell cluster sizes are the cause or the consequence of certain sexual behavior ("the results do not allow one to decide if the size of INAH 3 in an individual is the cause or the consequence of that individual’s sexual orientation, or if the size of INAH 3 and sexual orientation co-vary under the influence of some third, unidentified variable" ). Nonetheless, LeVay offers evidence from studies of rats and a "comparable hypothalamic nucleus, the sexually dimorphic nucleus of the preoptic area" (comparable because it is supposedly sexually dimorphic!) to support the theory that hypothalamic size (in rats, correlated with sex) is fixed by prenatal hormones and does not change with experimental changes in hormone levels (1036). (Spanier, Biological Determinism and Homosexuality. p. 40 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
When it is all said, and done, the work of LeVay is more suggestive than anything else. It certainly does not show that there is a hard and fast correlation between INAH3 size and sexual orientation. (Murphy, Gay Science The Ethics of Sexual Orientation Research, p.30)
Not that there weren’t reservations and problems. As LeVay himself pointed out at the end of his Science report, AIDS could have played a role in varying the sizes of INAH3. INAH3 could also be determined by one’s sexual behavior rather than being the cause of it. Or there could be some third factor that triangulates with sexual behavior and INAH3 clusters, mitigating the cause-and-effect between the two. (Archer, The End of Gay and the death of heterosexuality, p.132-133)
Were Science and the peer reviewers of the article fair and impartial towards this article? It may be argued no from reading what others wrote, both those advocating for and opposed to homosexuality.
Clearly the peer reviewers and Science’s editorial board allowed LeVay considerable leeway in his research design, explanatory framework, interpretations, and conclusions. (Spanier, Biological Determinism and Homosexuality. p. 43 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
To analyze validity, we can examine and critique a number of points in the construction of any scientific claim: the explanatory framework and premises on which it is based, the methods and design of the study, the presentation and manipulation of data and conclusions drawn, and the interpretations of the data and conclusions.
When the premises on which a study is based are faulty or highly questionable, the question being asked in the study is flawed. This occurs, more broadly, when the paradigm within which the study is conducted - the explanatory framework that guides the original question and the approach taken to answer it - is defective or questionable (Longino). In this case, measurements may be correct but whole conclusions may be questioned or deemed invalid. The framework or paradigm of an area of science can also influence the results obtained, as Stephen Jay Gould has shown in remeasuring the size of skulls studied by an eminent scientist in the nineteenth century.
Research results can be similarly faulty when a study is poorly set up, with improper or too few controls, with an inadequate sample size, with a non-representative or nonrandom sample. In this case, the methods and experimental design are often inadequate for scientific validity.
Data can also be manipulated improperly and misrepresented. For example, the effects of increasing dosages of a drug may be presented numerically but not displayed on a graph, when graphing would show a dose-response curve inconsistent with a study’s conclusions. In this and other ways, the conclusions stated about the data can be wrong or limited in ways not addressed by the author. Often the conclusions summarized in the abstract are simplified or overstated and are not supported by data buried in tables and diagrams.
The interpretations drawn from research conclusions can also be highly suspect. Here the premises on which the study is based, including previous research cited and the explanatory framework, play a big role.
By analyzing any study, we can locate where and how the authors make judgments affected by biases, and then we can draw our own conclusions about the limitations of the study as well as the ways that scientists incorporate their biases into their work - and how that affects what we can learn from scientific research. (Spanier, Biological Determinism and Homosexuality. p. 37-38 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
Several premises are embedded in LeVay’s introduction, in addition to the jump from studies of monkeys to humans. (1) The anterior hypothalamus in the brain exerts some control over sexual orientation in humans. (2) Size differences in one or more clusters of cells recognizable within the anterior hypothalamus of humans reflect differences in influence over sexual orientation, that is, cell cluster size somehow determines sexual behavior. This premise assumes that variations in INAH 2 and 3 are due to the difference that matters to LeVay - sexual orientation in men - rather than to other factors affecting the size of those cell clusters. (3) There exists such a thing as "male-typical sexual behavior" in humans, it differs from some other unnamed behavior, and it is the same thing as "sexual orientation,... the direction of sexual feelings or behavior toward members of one’s own or the opposite sex" (1034). As we critique this premise, we reveal LeVay’s assumption conflating sexual orientation with gender through the concept of "male-typical sexual behavior," that is, unspecified behavior based on the gender of the persons toward whom an individual is oriented ("sexually oriented toward women" or toward men). (4) Sexual orientation is based on biological influences that are specific to male and female identities. (Spanier, Biological Determinism and Homosexuality. p. 38-39 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
Other premises or assumptions built into LeVay’s explanatory framework include a dichotomy of "typical sexual behavior," oriented either to women (male-typical) or to men (unspecified). The author sidesteps the relationship of those concepts to actual sexual behavior, although he refers in his later discussion to insertive and receptive roles among gay men While LeVay seems to be challenging the significance of gender (he uses "sex") in brain differences, his framework and premises strongly depend on bipolar gender categories.
LeVay’s introduction setting the framework for his approach moves quickly through traditional explanations of sexual behavior (from the fields of psychology, anthropology, and religion/ethics) to "the biological basis of sexual orientation," citing the failures of methods involving studies of chromosomes, hormones, and brain structures to "establish any consistent differences between homosexual and heterosexual individuals" (1034).
He has chosen the anterior hypothalamus as the "likely biological substrate for sexual orientation" because in nonhuman primates, damaging that part of the brain "impair[s] heterosexual behavior without eliminating sexual drive" (1034). The studies he cites, assume that the "heterosexual behavior" of monkeys is the same thing as "male-typical" sexual behavior, that is, mounting of females by male monkeys. Uncited is the evidence that mounting or presenting, whether in monkeys or mice, is not sex-specific. Females mount males and other females, as males also mount other males (Bleier 87,174). The edges of "male" and "female" categories of behavior are blurred in monkeys and mice, as they also are in humans. "Sexual drive" in the studies LeVay cites means masturbation, a conclusion that is already somewhat questionable given the constructed and ambiguous nature of the terms "male-typical sexual behavior" and "sex drive."
What is this distinctively male-typical sexual behavior that distinguishes heterosexual men from heterosexual women such that the larger size of a region of the brain "could be involved in the generation of male-typical sexual behavior" (1035; my emphasis)? What does "typical male sex behavior, such as attraction to females" (Nimmons 66, quoting LeVay) mean? Does the person - male or female - desiring women exhibit some male-typical sexual behavior by wanting to insert a penis into a vagina? Where does that leave lesbians? Is desiring to insert a penis into an anus very different from wishing to insert one into a vagina? Similar or different for whom? (Spanier, Biological Determinism and Homosexuality. p. 39 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
Another example of LeVay’s selectivity in choosing similar studies is found buried in note 10; "INAH 1 is the same as the nucleus named the ’sexually dimorphic nucleus’ and reported to be larger in men than in women [D. F. Swaab and E. Fiers, Science 228,1112 (1985)]. My results support the contention by Allen et al., (6) that this nucleus is not dimorphic" (1037). Obviously, the result of Swaab and Fliers’s study conflicted with those of Allen’s et al. on INAH 1. LeVay simply notes that his study agrees with the latter; his data on INAH 2, in contrast, does not (which is explained away by age). While this may seem like a travesty to those unfamiliar with how science is actually done, it is not unusual at all to have seriously conflicting results in certain areas of research, brain and behavior for one (Fausto-Sterling, Myths). For some scientists, such contradictory results signal poor researchers, a poorly conceptualized research design, or a deeply flawed explanatory framework. For others, particularly those who accept the explanatory framework of a whole field, the uncertainties are the price paid for investigating complex or ill-understood phenomena. Clearly the peer reviewers and Science’s editorial board allowed LeVay considerable leeway in his research design, explanatory framework, interpretations, and conclusions. (Spanier, Biological Determinism and Homosexuality. p. 43 in Same-Sex Cultures and Sexualities An Anthropological Reader edited by Jennifer Robertson.)
What critical and objective conclusion can be gained from a close look at LeVay’s study published in the journal Science? Both the journal, and LeVay came under intense scrutiny. Science was faulted for not following their own procedures and policies for publication of articles. LeVay acknowledges it was not an impartial study by an impartial researcher. The results themselves are open to methodological concerns, small sample size, determination of the sexual orientation of subjects from which the brain tissue samples were taken, and drawing conclusions from parallel animal research. Finally, no follow up research has replicated his original results.
Hammer’s Gay Gene
The publication of Hamer’s study that has been used to herald the finding of a gay gene has had similar consequences of acclaim and criticism.
He published a paper with this findings, which proved to be so media-friendly that he wrote a book about the whole thing, in which he said several times that as far as he knew there was no such thing as a gay gene, and that, even if there was, he hadn’t found one. (Archer, The End of Gay and the death of heterosexuality, p.136)
While in the paper published in Science Hammer and his colleagues claim only to have found an association between markers in the Xq28 region and a behavioral outcome (homosexuality), in more popular writings (Hammer and Copeland 1994, 1998; LeVay and Hammer 1994) they blur the distinction between association and causation in a way that more strongly suggests a genetic basis for homosexual behavior (Allen 1997). (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 68)
Back in the early part of this decade, after he got fed up with so many of his friends dying from Kaposis sarcoma, he decided to look into a possible genetic predisposition for gay men to get this anomalous and now predominantly AIDS-related cancer. He didn’t find any, but in the course of studying the gay-man DNA he’d collected, he noticed a greater than average coincidence of a certain genetic marker along a certain part of the long arm of the X chromosome. After a little more casting about, he came up with some results that showed the marker, Xq28, seemed to played some role in the sexual orientation of somewhere between 5 and 30 percent of gay men. (Archer, The End of Gay and the death of heterosexuality, p.136)
This was not, as the media chose called it, a gay gene, but persuasive evidence of a genetic factor or factors, which in this section of the gay community at least, are sex liked. As previously, the genotype remains obscure. It could be of indirect relevance (e.g. relating to some behavioral or gender role phenotype which interacts with other influences on sexual development). It is unlikely to be a gene which determines sexual orientation per se. (Bancroft, Homosexual Orientation The search for a biological basis. p.439)
This study does not identify a gene for homosexuality, as many ill-informed reports have had it. In fact, the chromosomal region in question is large enough to contain several hundred genes. Moreover, the genetic action at work is not decisive by itself because there were seven pairs of gay brothers in the study who did not share the same genetic commonality at this region. (Murphy, Gay Science The Ethics of Sexual Orientation Research, p.32-34)
In both report and book, Hamer made it clear that he did not figure he’d found a gay gene. He’d found a conspicuous concurrence of a specific genetic marker among self-declared homosexuals. The findings were statistically significant, but the relationship of the genetic marker to the behaviour was as yet undetermined (Archer, The End of Gay and the death of heterosexuality, p.135)
Hamer’s study was set up in a way that it almost guaranteed success, in that he would find what he was looking for. The study was of 40 brother pairs of homosexuals from families in which the pattern of occurrence of homosexuality suggested inheritance through the mother. In the comparison of the x-chromosomes of the homosexual brothers, 64% of the brother pairs shared an identical section of DNA, a different marker for each pair.
Hamer and his colleagues also had their research published in an article by Science in 1993, A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation by Dean H. Hamer, Stella Hu, Victoria L Magnuson, Nan Hu, & Angela M. L. Pattatucci. Hamer and others on this research team are self-avowed homosexuals. In addition to widespread popular media coverage similar to LeVay’s study, there were investigations by U.S. governmental agencies of Hamer’s research. The initial investigation was concerning possible fraud, the selective use of data, where pairs of brothers whose genetic makeup contradicted the finding were not included in the findings. This investigation was conducted by the National Institutes of Health, and was followed by an investigation of the Federal Office of Research Integrity. A co-worker within Hamer’s group of researchers made the claim and it was first reported in 1995 article in the Chicago Tribune newspaper. In December of 1996 the second investigation was closed and no charges were filed against the researchers.
Hamer’s criticism came from both sides of the issue, those for and those against homosexuality. It was common criticism of methodology by many people, but as with LeVay for those advocating for homosexuality it was direct and pointed. Sample size and how subjects were included in the study was noted. In this study, it included only those where transmission of the trait was from the mother’s side. In spite of it being called a gay gene the actual study was looking for genetic markers and not for the genes themselves. Most interesting is that initially the research was not to look for a gay gene. The study was to determine if homosexuals were genetically predisposed to alcoholism and the AIDS-related skin cancer, Kaposis sarcoma. This study has also not been replicated. Another study by Canadian researchers has found different results.
Failure to use controls limits the conclusions in the research reported by Hammer and his colleagues (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 66)
Taken as a whole, Hamer’s study faces various methodological problems, its results are open to various interpretations (several which are more plausible then the existence of a gay gene), and it has not been replicated. Hamer’s study, which has been taken by many to be the centerpiece of the emerging research program, actually exemplifies many of its problems. (Stein, The Mismeasure of Desire, p. 221)
Hamer and associates did not identify genes that cause same sex erotic attraction. They identified common markers for male same-sex eroticism among related individuals with the same trait. To enhance their chances of finding positive results, Hamer and associates limited expression of the trait to maternal transmission. Therefore, genes for the trait would be specific to the X chromosome. Consequently, gay men with gay fathers-who might transmit the trait on the Y chromosome-were excluded from the study. (Kauth, True Nature, p. 138-139)
Hammer and Copeland note that the gay gene has not been isolated and that Xq28 plays some role in about 5 to 30% of gay men. The broad range of these estimates is proof that much more work remains to be done (1994,146). (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 67)
Genetic linkage studies are particularly complicated, technical, and vulnerable to confusion and misinterpretation because such tiny bits of material are said to influence such major traits as sexual attraction. Consequently, disagreements among scientists about these analysis are many. (Kauth, True Nature, p. 140)
Hamer identified five genetic markers for maternally transmitted same-sex eroticism in males. Even so, this type of work is in its infancy, and Hammer’s findings need to be confirmed by independent researchers. The five markers encompass hundreds of genes. (Kauth, True Nature, p. 216)
Hamer’s effort to generalize from genes to behavior would be immensely complicated by a confrontation with the actual complexities of human psychology, social organization, and cultural forms. Starting from a presupposition that sexuality is an either-or matter and that gay and straight are essential, timeless orientations-his decision to exclude bisexuals from the study was, he says, intentional-Hamer sets up his research in such a way to bypass any information to the contrary and then comes up with evidence for a gene that in turn seems to confirm his initial categories. (Clausen, Beyond Gay or Straight, p.126-127)
Rice et al. (1999) report failure to replicate Hammer’s work. This research group was unable to find a link between male homosexuality and Xq28, and maintains that gay brothers are no more likely than straight brothers to share the Xq28 genetic marker. Further, this group found little evidence supporting Hammer’s claim of maternal transmission. Wickelgren (1999) reviews findings reported at the 1998 meetings of the American Psychiatric Association which also failed to replicate the findings of Hammer and concludes that there is very little evidence supporting the hypothesis that Xq28 is a genetic marker linked to homosexuality. (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 67)
The evidence for a genetic component for homosexuality is hardly overwhelming. Numerous studies that purport to prove the existence of a genetic aspect to homosexuality are either anecdotal or seriously flawed. Homosexuality is often poorly defined and researchers use a variety of behavioral measures. The sample sizes are too small and recruitment of subjects is biased. (McGuire, Is Homosexuality Genetic? A Critical Review and Some Suggestions. p. 140-141 in Sex, Cells, and Same-Sex Desire: The Biology of Sexual Preference editors John P. De Cecco, PhD and David Allen Parker, MA)
To be specific, it is necessary to investigate the biological research to determine exactly what it has to say about homosexuality. The studies of LeVay and Hamer, for example, which are often associated with the biological argument, were limited in scope and never have been satisfactorily replicated (Crewdson 1995). In addition, both studies used only male subjects; therefore, the data only support the biological argument as applied to male homosexuals. Finally, both LeVay’s and Hamer’s studies draw on a wide variety of scientific studies that contain varying theories of male homosexuality, many of which conceptualize male homosexuality as pathology. (Brookey, Reinventing the Male Homosexual: The Rhetoric and Power of the Gay Gene, p. 7)
The argument for homosexual immutability betrays a misreading of the scientific research itself. Nothing in any of these studies can fully support the idea that homosexuality is biologically immutable, each study leaves open the possibility that homosexuality is the result of a combination of biological and environmental factors, and several suggest that homosexuality may be tied to a predisposition in temperament that could manifest itself in a number of ways. All, agree that biological, social, and psychological factors interact to produce and change the signs of homosexuality. Furthermore, these studies cannot comment effectively on the frequency of homosexuality in the general population. (Terry, An American Obsession p.394)
As this survey indicates, research currently cited in support of a biological model of human sexuality is methodologically deficient, inclusive, or open to contradictory theoretical interpretations. In addition, much of such research concentrates on animal studies and therefore has little relationship to human behavior which is generally affected by cultural values. Therefore, this paper basic question is: How convincing is the biological evidence that the details of human sexuality are directly due to innate traits and processes? The answer is the evidence is far from persuasive. We may conclude that the biological perspective on human sexuality has not yet made a substantial contribution to the balanced biosocial synthesis that the Baldwins (1980) have recommended.
This conclusion is not intended to imply that biology has nothing to do with human sexuality (since the two, are of course, inextricably intertwined). It means simply this: The claim that biological factors have an immediate, direct influence on such things as sexual identity, behavior, or orientation remains unproven. When biology seems to be critical in such matters, an intervening cultural factor is often more immediate. (Hoult, Human Sexuality in Biological Perspective: Theoretical and Methodological Considerations, p.150-151 in De Cecco and Shively, Bisexual and Homosexual Identities: Critical Theoretical Issues editors John P. De Cecco and Michael G. Shively)
Although we have sought to provide a balanced understanding of the issues involved in study and treatment, review of extant findings has led to several conclusions which inform the book. In the first place, while genetic influences might play some role in determining sexual orientation, evidence reported to date does not permit such a conclusion. Neither do extant studies of biological factors such as hormonal changes in prenatal life among men later identifying as gay support the hypothesis that such factors have an important role in explaining same-gender sexual orientation.
Findings from developmental studies suggest that sexual orientation is much more fluid across the course of life than has often been recognized. (Cohler and Galatzer-Levy. The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p.9)
What is important is to understand what is now commonly spoken of as sexual orientation. Whether it is heterosexual, homosexual, or bisexual. And most important of all is the biological role that may play in one being a heterosexual, homosexual, or a bisexual.
There are no sexual instincts in man. Human sexual behavior, as we have seen, varies widely from individual to individual and from culture to culture, and human sexual behavior is entirely dependent upon learning and conditioning. The tastes, preferences, goals, and motives that determine the individual’s pattern of sexual behavior are acquired in the context of his unique experiences and are in no sense innate or inherited. Only if this fact is thoroughly integrated and absorbed is it possible to discuss human sexual phenomena from a scientific standpoint. (Churchill, Homosexual Behavior Among Males: A Cross-Cultural and Cross-Species Investigation, p. 101)
Like other aspects of human behavior, sexual orientation is the outcome of a complex interplay of different factors, some of them physical, some of them hereditary, but most of them environmental. Environmental influences include general cultural habits and expectations, as well as particular characteristics of the individual’s family upbringing and person circumstances. No single, predominant cause for all cases of homosexual orientation is ever likely to be found. (West, Homosexuality Re-Examined, p.320)
Although there is no reliable evidence that sexual orientation is genetically inherited, neither is there evidence for the conclusion by Hoult (1984) that it is the result of social-learning. The available evidence forces one to consider that neither nature or nurture provides the sole answer to the cause of sexual orientation, either heterosexual or homosexual. One may consider that genetic material (nature) is acted upon during a critical period by environmental influences (nurture) or, in a more general sense, that neither influence can act without the other. Human beings are born with the potential for sexual behavior. (Haynes, A Critique of the Possibility of Genetic Inheritance and Homosexual Orientation,” p. 108-109 in Sex, Cells, and Same-Sex Desire: The Biology of Sexual Preference editors John P. De Cecco, PhD and David Allen Parker, MA)
All available scientific evidence points to the conclusion that sexual orientation, be it heterosexual, ambisexual, or homosexual, is a result of the interaction of genotype and environment. People are born with the innate ability to perform sexually, but the focus of that performance is no more immutable than language skills. Further, there is evidently great plasticity in orientation, as one moves from one point on the sexual continuum to another, for differing lengths of time, and at different periods of one’s life. The constraints placed by social order on particular orientations have no basis in biology. Thus, homosexuals should seek their liberation through political and social efforts rather than biological research. (Haynes, PhD James D. A Critique of the Possibility of Genetic Inheritance and Homosexual Orientation, p. 111 in Sex, Cells, and Same-Sex Desire: The Biology of Sexual Preference editors John P. De Cecco, PhD and David Allen Parker, MA.)
Social theory and the study of the lives of gay and straight men and women converge to show that the experience of sexual desire is not fixed but varies across the course of life.
Sexual orientation should not be viewed from an essentialists perspective that regards sexual desire as predetermined by either innate or developmental factors; sexual desire is fluid and changing in its significance for society and persons over historical time and in lived experience within lifetimes. Little is known about factors leading to either heterosexuality or homosexuality. The meaning of same-gender desire is founded in social and historical circumstances, which change over time and across generations or cohorts. Social contexts and personal life circumstances alike influence the presently told life story narrated and collaboratively re-constructed in psychoanalysis. (Cohler and Galatzer-Levy, The Course of Gay and Lesbian Lives: Social and Psychoanalytic Perspectives, p. 421)
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