NPR Letters on the Biological Basis of Homosexuality
This is an early draft of an article I recently published, with Richard Pillard, in the "Harvard Mental Health Letter" entitled something like "The Innateness of Sexual Orientation." (Copyright be damned.) Unfortunately, I don't discuss Hamer's recent X-linkage finding in "Science." ________________________________________________________________________________
Recently much media attention has focused on the question of what causes some people to be homosexual and others to be heterosexual. There are at least two reasons for this attention. First, gay rights issues have been prominent on the national agenda, and some commentators have argued that etiology is pertinent to their resolution. Second, scientists have recently reported several studies supporting the possibility that sexual orientation is primarily innate, rather than psychosocially determined. The worth and implications of these studies have been hotly debated. We believe that at least some of the studies are scientifically valuable and that biological theories of sexual orientation are the most promising currently being investigated.
Two lines of evidence suggest that sexual orientation is influenced by innate processes: neuroendocrine (including neuroanatomical) and genetic studies. Neuroendocrine theories are more fully developed and have spurred far more research. At the same time, however, cumulative empirical support for neuroendocrine influences is perhaps more tenuous than that for genetic influences.
Neuroendocrine Studies
Neuroendocrine views were originally motivated by the observation that gay men are like most women in being attracted to men; lesbians are like most men in their attraction patterns. The neuroendocrine view posits a process that is analogous to the differentiation of the external genitalia, about which much is known. At the risk of oversimplifying, the basic neuroendocrine hypothesis is that sexual orientation is determined by the early (probably prenatal) effects of androgens on relevant neural structures. If these structures are effectively exposed to high levels of androgens, then they are masculinized, and attraction to women will result in adulthood. If they are not exposed to high levels of androgens (either because there are low amounts of androgens or because the relevant tissues are insensitive to their effects), the structures do not masculinize, and attraction to men will result. Several lines of research support the likelihood of neurohormonal influences on human sexual orientation, and we consider them from the least to the most direct.
Studies of rodents have shown clearly that some sex-typical sexual behavior can be affected by altering early androgen levels. Adult female rats and mice that received male-typical doses of androgens sufficiently early will, under certain circumstances, display some male mating behaviors such as mounting and reduced lordosis. Conversely, males deprived of early androgens will show the opposite pattern of behavior. It has been widely acknowledged--by both sides of the biology debate--that neither mounting nor lordosis behavior is directly analogous to human sexual orientation, in which the sex of attraction is primary. Nevertheless, these studies have been heuristically valuable in suggesting how sex-typical behavior differentiates under the influence of early androgen exposure. Furthermore, some recent studies of various nonhuman species have supported the possibility of neuroendocrine influences on preference for male versus female partners.
Perhaps the single most reliable finding in all of homosexology is that gay men and lesbians recall, on average, substantially more gender atypical behavior in childhood than do heterosexuals of the same sex. Gay men often report that they were considered Òsissies,Ó and lesbians Òtomboys,Ó though there are plenty of exceptions in both groups. This supports the idea that homosexual people have been subject to some influences more typical of the opposite sex and is thus consistent with a neuroendocrine hypothesis. Furthermore, studies of primates including humans have shown that some patterns of sex-typical childhood behavior can be altered if fetuses are exposed to unusual levels of androgens. Female rhesus monkeys exposed prenatally to high levels of androgen show elevated rates of male-typical (rough-and-tumble) play behavior.
Similar findings have come from studies of girls and women with congenital adrenal hyperplasia (CAH). CAH is a genetic disorder that causes a fetus to secrete large amounts of androgens from the adrenal glands, enough so that newborn girls with the condition often have virilized genitalia. Several studies have found high rates of masculine behavior in girls with CAH, including preference for masculine toys, increased rough-and-tumble play activity, and other ÒtomboyishÓ behavior. Even more importantly, some studies have found elevated rates of homosexual feelings among adult women with CAH compared to control women. Women prenatally exposed to DES, a chemical that causes masculinization of sexual behavior in some animals, also have an elevated rate of homosexual feelings. At the same time, it should be noted that only a minority of women with a history of DES exposure or CAH admit to homosexual feelings. Furthermore, there is no model of male homosexuality that maps as neatly onto the hypothesized neuroendocrine route as does CAH for female homosexuality.
The study most relevant to neuroendocrine theories of male homosexuality, and certainly the most widely-discussed biological finding, is that of Simon LeVay. LeVay examined the brains of gay men who had died of AIDS, as well as those of presumably heterosexual men and women who had died of a variety of causes. He studied cell-groups (nuclei) in an area of the hypothalamus that had been implicated by animal work as important to sexually-dimorphic sexual behavior. Two of the nuclei had previously been shown to be larger in men than in women, and LeVay found the same sex difference for one of the nuclei (INAH-3) when he compared heterosexual men and women. More important for sexual orientation, he found that INAH-3 was as small in gay as in heterosexual women. The differences were statistical rather than absolute, i.e., there were some gay men and heterosexual women with INAH-3 as large as those of most heterosexual men. This shows that the size of INAH-3 cannot be the sole cause of sexual orientation; indeed, it may not be a cause at all. But it does suggest that some aspects of the brainÕs sexual differentiation are shared by gay men and heterosexual women, and it is noteworthy that these include a portion of the brain that animal work shows to be involved in sexual behavior.
LeVayÕs study has been intensively scrutinized, and several criticisms have been made. These include the concern that the difference may have been due to AIDS, that the ÒheterosexualÓ sample could have included some homosexual subjects (because medical records did not include sexual histories), and that the observed difference could have been an effect, rather than a cause, of homosexuality. These criticisms are unimpressive. Some of the heterosexual men died of AIDS as well, and their average INAH-3 volume was no smaller than that of heterosexual men who died of other causes. Recent surveys have suggested that the incidence of homosexuality is rather low, and so it is unlikely that the heterosexual control groups contained a significant proportion of homosexual people. (And if they had, LeVay would have been even less likely to find the results he did.) Finally, although the possibility that the anatomical differences resulted from behavioral differences cannot be dismissed altogether, research on some other mammalian species suggests that sex differences in the hypothalamus develop early in response to innate hormonal influences and are not modified by later experiences.
At least one other neuroanatomical study has found an association between male sexual orientation and brain structure that tracks the heterosexual sex difference. Laura Allen and Roger Gorski found the anterior commissure of the corpus callosum to be relatively larger in heterosexual women and homosexual men compared with heterosexual men. This portion of the brain is unlikely to be directly involved in sexual behavior. Rather, the study suggests that neuroendocrine influences may have more general effects.
Genetic Studies
Our own work has investigated the origins of sexual orientation using techniques from human behavioral genetics. We have attempted to elucidate the degree to which people who differ in their sexual orientations do so for genetic versus environmental reasons. Both male and female sexual orientation run in families, with gay men having more gay brothers and lesbians more lesbian sisters than do same-sex heterosexuals. (It is less clear at this point if gay men have more lesbian sisters, and vice versa.) Of course, this is insufficient to show that genes matter, because a trait can run in families for environmental reasons as well (e.g., Catholicism). In order to distinguish between genetic and familial environmental influences, more sophisticated designs are necessary. Perhaps the most widely used design in human behavioral genetics is the classical twin study, in which monozygotic (MZ) and dizygotic (DZ) twin pairs are examined for their similarity on the trait of interest. The rationale for this design is that because both MZ and DZ twins are typically reared together, they are equally similar environmentally. However, MZ twins are identical to each other genetically, while DZ twins are only as genetically similar as ordinary brothers. Thus, if MZ twins are more similar than DZ twins on average in their sexual orientation, the importance of genetic factors is supported. An explicit assumption of this design is that the environmental factors important for sexual orientation are no more similar for MZ than for DZ twins. This "equal environments assumption" has been criticized. However, in studies of other personality traits, those aspects of the environment that are particularly similar for MZ twins (such as being dressed alike) have not appeared to be very important in causing behavioral similarity.
There have been several twin studies of sexual orientation. The earliest, by Franz Kallmann in 1952, found an amazing 100% concordance rate among 37 male MZ twin pairs, compared to a much lower rate of 12% for 26 male DZ twin pairs. Kallmann's study had enough methodological problems that its specific results, particularly the 100% MZ concordance rate, cannot be taken very seriously. On the other hand, no one has provided a satisfying explanation of how the methodological problems could wholly discredit evidence for genetic influences. Thus, it is somewhat surprising to us that nearly 40 years passed before others attempted to follow up his promising results systematically.
The largest genetic studies to date have been our own, one with men and one with women. These studies included not only MZ and DZ twins, but a third group, homosexual subjects with adoptively-related same-sex siblings, who are genetically least similar and thus should be least similar in their sexual orientations. Our two studies obtained results that were quite similar to each other. In the male study, MZ twins of our gay index subjects had a 52% chance also of being gay, compared to a 22% rate for their DZ twins and an 11% chance for their adoptive brothers. In the female study, MZ twins had a 48% chance of also being lesbian, compared to a 16% rate for DZ twins and a 6% rate for adoptive sisters. Note that similarity in sexual orientation corresponded closely with genetic similarity in both studies.
Quantitative analyses provide heritability estimates of the relative proportion of genetic causation, and our heritabilities were consistently above 50%. Thus, both studies were consistent with moderate to strong genetic influences on sexual orientation. Of course, both studies yielded figures lower than the 100% suggested by Kallmann. Two newer twin studies more or less supported ours. One found concordance rates that were lower than ours, the other found higher rates, but both found MZ higher than DZ rates.
All recent studies find that MZ twins often differ in their sexual orientations, which shows that sexual orientation cannot be completely explained by genes. Environment must play its part. On the other hand, we emphasize that environmental pathways can be biological as well as psychosocial. One of the most interesting questions to stem from the recent twin studies is what environmental factor could affect MZ twins differently enough to give them opposite sexual orientations.
One other twin study is worth mentioning because it contained what many consider to be the ideal (if rare) subjects: twins reared apart. In this study both of two male pairs were concordant for adult homosexual feelings and behavior, which would be highly unlikely if genetic factors were unimortant. Although none of four female pairs was concordant, this sample was too small to be conclusive; of course it provided no support for genetic factors affecting female sexual orientation.
Although we believe the available evidence is strongly suggestive of genetic influence on sexual orientation for both men and women, one serious methodological limitation of available studies prevent them from being definitive. The studies have recruited subjects via advertising in gay- and lesbian-oriented publications. They may have had an overrepresentation of concordant pairs because such studies might be more appealing to gay men and women with gay twins. Such bias is not very serious unless it was stronger for MZ than for DZ twins, and we have no reason to suspect that such differential bias occurred. But only a study using systematic ascertainment could exclude this possibility, and unfortunately none exists.
Research that helps settle some questions raises new ones. By what pathway do genes lead to the expression of atypical childhood behavior and homosexual orientation? Our studies have usually been discussed as supportive of neuroendocrine theories, and genetic influences might indeed be neuroendocrine. One could imagine a gene that led a fetus to secrete unusually high or low levels of prenatal androgens during brain differentiation, or alternatively, to be especially sensitive or insensitive to androgens. But genetic influences on sexual orientation would not have to be neuroendocrine in nature. For example, genes could influence personality (say, independent thinking or unconventionality) that could increase the chance of adopting a homosexual identity. For reasons we discuss later, we doubt that the indirect route through personality is typical, and instead believe that genetic influences operate via a neuroendocrine pathway. But our studies have had nothing so far to say about this.
The Biology Debate
A thorough and thoughtful critique of the biological evidence has been provided by Byne and Parsons, in a recent version of Archives of General Psychiatry. They argue that the biological case is quite weak. Byne has asserted that reviewing the biological evidence is akin to "adding zeroes" because no one study is methodologically strong enough to establish the biological case definitively. While we agree that no one study has established the case for biological factors, we disagree that their sum is "zero" evidence in favor of biological hypotheses. It is difficult if not impossible to do perfect studies using human subjects. But if different kinds of studies with different research strategies (with different methodological inadequacies) converge to similar conclusions, then the critic who rejects the cumulative evidence begins to sound strained. For example, disregarding other research one might reasonably worry (as Byne and Parsons do) about the role of postnatal socialization of girls with CAH, since some are born with virilized genitalia and they and their parents know about their condition, and for this reason may be treated more like boys. But what if one knows that the only studies that have investigated this possibility have failed to confirm it? Furthermore, it has been well-established that androgen administered at critical periods can masculinize female rhesus monkey's play and sexual behaviors. How likely is it that the apparently analogous behavioral masculinization of some CAH females has a completely separate explanation?
A second complaint we have of Byne and Parsons' otherwise useful critique is its one-sided perfectionism. Scientific theories are not evaluated in a vacuum. Rather, their evidentiary basis and plausibility are compared to those of the competition. There have been two main psychosocial competitors to innate theories of sexual orientation: psychoanalysis and socialization theory. Psychoanalytic theories of homosexuality, which have stressed the role of family psychodynamics, suffer from the same well-known problems as does the corpus of psychoanalysis, particularly the inadequacy of impressionistic data collected during psychotherapy under uncontrolled conditions. Although there has been some support for the psychoanalytic prediction that fathers are somewhat distant from their gay sons, this is a rather small effect that is easy to explain on other grounds, such as fathers' intolerance of their sons' gender-atypical behavior.
In contrast to psychoanalytic theory, which has largely been abandoned by mainstream science, theories describing the socialization of gender roles are quite respectable. We are certain that some sex differences result from socialization by parents, peers, and society. We are nearly as certain that differential socialization by these agents cannot explain why some people become homosexual and others heterosexual. For example, there is no good evidence suggesting that parents of homosexual people socialize their children differently than do parents of heterosexual people; indeed, the available evidence suggests they do not. Socialization theory of sex differences emphasizes processes such as positive reinforcement of conventional gender norms and modeling. But in our society homosexual people are obviously not rewarded for their unconventional behavior, and the vast majority of their potential role models are heterosexual. If anything, socialization mechanisms in our society have been arranged to insure heterosexual outcomes.
Byne and Parsons recognize the necessity of providing a plausible competitor to the theories they criticize. Their attempt is an amalgam of psychoanalytic and socialization theories, suggesting that boys with certain familial influences and (genetically-influenced) personality traits might have unusual "nonerotic experiences in childhood that may contribute to the subsequent emergence of homoerotic preferences." This "theory" has the unusual dual deficiencies of vagueness and implausibility. It is vague because the personality traits, familial influences, and childhood experiences are mostly unspecified. It is implausible because, for example, there is no personality characteristic besides childhood gender typicality that has been shown to differ between homosexual and heterosexual people. Thus, Byne and Parsons have failed to provide a plausible alternative theory to explain the data that biological theories have generated and more generally, to account for the development of sexual orientation.
We do not argue that the biological evidence is strong enough to settle the debate over origins of sexual orientation. We acknowledge the need for replication of the most promising studies, including LeVay's, Allen and Gorski's, and our own. Nevertheless, we are far more optimistic than some critics of the biological evidence about the ultimate utility of biological approaches for explaining human sexual orientation. The biological theories are far more promising than any existing psychosocial theory, and they deserve the attention of scientists and funding agencies so that the "biology debate" can be resolved in the laboratory, as it certainly cannot be in these pages.
From al715@yfn.ysu.edu Tue Jun 27 22:01:58 1995
Date: Wed, 28 Jun 1995 01:20:17 -0400
HOMOSEXUALITY: IT'S IN YOUR GENES
(NOT JUST YOUR JEANS!)
Part I
Mitch King
Charlottesville, VA
WASHINGTON, 93 Jul 16—A group of researchers from the National Institutes of Health have discovered statistical evidence that one form of male homosexuality is genetically transmitted from mothers to their sons through the X chromosome. The study involved pedigree and DNA linkage analyses on 114 families of homosexual men.
Subjects included 76 self-acknowledged homosexual men and their relatives over age 18 recruited through a Washington DC HIV clinic and local homophile organizations, and 38 pairs of homosexual brothers and their relatives recruited through advertisements in local and national homophile publications. Participants were white non-Hispanic (92%), African American (4%), Hispanic (3%), and Asian (1%). Sexual orientation was assessed by the Kinsey scales, and subjects rated themselves on four aspects of their sexuality: self-identification, attraction, fantasy, and behavior. Most of the men (average age 36) reported experiencing their first same-sex attraction by age 10, which was prior to the average age of puberty (age 12).
For the first sample, (the 76 men from the Washington DC area), D. H. Hamer, S. Hu, V. L. Magnuson, N. Hu, and A. M. L. Pattatucci found that 13.5% of the brothers, 7.3% of the maternal uncles, and 7.7% of the sons of maternal aunts of homosexual men were self-acknowledged homosexuals--compared to the background rate of 2% which was an estimate obtained from 717 randomly selected males who were the subjects of previous research. Other significant findings were that 5.4% of the sisters of homosexual men were self-acknowledged lesbians (versus a 1% background rate), and 4.7% of the of the brothers of lesbians were self-acknowledged homosexuals (versus a 2% background rate). Homosexuality among fathers and all other types of paternally related relatives of the homosexual subjects was not significantly greater than the background rate.
Although higher than the background rates, the observed rates of homosexuality in the maternally derived uncles and male cousins of gay men in the first sample were lower than would be expected for a simple Mendelian trait, so the researchers hypothesized that there might be at least two types of male homosexuality--one which was male-limited and maternally inherited versus one which was sporadic, not sex-limited, or not maternally transmitted. To test this hypothesis, Hamer et al. recruited the second sample--the 38 families in which there were two homosexual brothers.
If their hypothesis concerning the existence of two types of homosexuality was correct, one would expect to see higher rates of male homosexuality in the maternally derived relatives of the second sample than in the first, and indeed, this is what was observed: 10.3% of the maternal uncles and 12.9% of the sons of maternal aunts of the homosexual brothers were, themselves, self-acknowledged homosexuals. Rates of homosexuality among the paternally derived male relatives were unchanged, or decreased compared to the first sample.
For the linkage analysis, DNA from 40 pairs of homosexual brothers (38 from the sib- pair pedigree study, and 2 from the random sample) and from their available mothers and siblings was studied and typed for a series of 22 markers that span the X chromosome. A significant linkage between homosexual orientation and markers in a region of the X chromosome known as Xq28 was detected--33 sib-pairs (82.5%) had inherited the same genetic information at all five markers within this region, whereas 7 pairs (17.5%) showed differences at one or more markers. The probability that such coinheritance could occur by chance alone is much less than 1.0%. As the research report states, "it appears that Xq28 contains a gene that contributes to homosexual orientation in males".
The 7 pairs (17.5%) of homosexual brothers who did not coinherit all of the Xq28 markers suggest that other factors, including nongenetic ones, play a role in determining sexual orientation. There was no significant evidence for linkage between sexual orientation and markers lying outside of Xq28, however, the researchers acknowledge that a much larger sample would be required to stringently eliminate all other regions from playing a role in sexual development in a small proportion of families.
Reference: Hamer, D. H., Hu, S., Magnuson, V. L., Hu, N., and Pattatucci, A. M. L. "A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation", Science, Vol 261, 321-327, 16 Jul 93. Science is published weekly by the American Association for the Advancement of Science, Washington, DC.
Unrestricted reproduction or electronic transmission is authorized when due credit is given to the author.
HOMOSEXUALITY: IT'S IN YOUR GENES
(NOT JUST YOUR JEANS!)
Part II
Mitch King
Charlottesville, VA
WASHINGTON, 94 Dec--Two Canadian researchers have discovered a statistical relationship between the number of ridges on men's fingertips and homosexuality, contributing additional evidence to the theory that sexual orientation can be influenced by biological events that occur at conception or early in fetal life. Specifically, J. A. Y. Hall and D. Kimura of the University of Western Ontario examined the fingerprints of 66 homosexual and 182 heterosexual men, comparing the number of ridges on the index finger and thumb of the left hand with the number of ridges on the index finger and thumb of the right hand.
If the number of ridges on the index finger and thumb of the left hand exceeds the number of ridges on the index finger and thumb of the right hand, one's fingerprints are said to exhibit leftward directional asymmetry. Hall and Kimura found such leftward directional asymmetry in the fingerprints of 30% of their homosexual subjects versus 14% of their heterosexuals.
Sexual orientation was measured by having all subjects rank themselves, in terms of fantasy and experience, via the Kinsey scale.
The number of ridges on the fingertips is largely determined at the moment of conception by genetics, subject to modification by local environmental factors (local hormone levels, etc.) up to the 16th week of fetal life. Only extensive mechanical damage alters the number of ridges after this time. According to Hall and Kimura, a significant statistical correlation between a prenatally determined characteristic such as one's fingerprints and an adult behavioral trait such as one's sexual orientation is consistent with previous research suggesting an early biological contribution to adult sexual orientation.
Reference: Hall, J. A. Y. and Kimura, D. "Dermatoglyphic Asymmetry and Sexual Orientation in Men", Behavioral Neuroscience, Vol. 108, No. 6, 1203-1206, Dec 94. Behavioral Neuroscience is published bimonthly by the American Psychological Association, Washington, DC.
Unrestricted reproduction or electronic transmission is authorized when due credit is given to the author.
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Subject: Fwd: Homosexuality in the animal kingdom
References: <FkinseyUR6da_3J3@clarinet.com
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From clari.feature.kinsey:
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From: clarinews@clarinet.com (Dr. June M. Reinisch, Ph.D.)
Newsgroups: clari.feature.kinsey
Subject: Homosexuality in the animal kingdom
Message-ID: <FkinseyUR6da_3J3@clarinet.com
Date: 7 Jan 93 05:08:03 GMT
Jan. 3, 1993
Dear Dr. Reinisch: Have you ever heard of homosexual practices among wild animals? I never have. If it doesn't occur, I think that could be real evidence that people, too, are not ``born that way'' but that it is a learned trait. I think it is also quite likely that homosexual and other sexual practices are addictive. An addicted person would no doubt feel like he was born that way.
Dear Reader: Thank you for your letter. I first want to say that homosexuality, like heterosexuality and bisexuality, is a sexual orientation, not a sexual practice. Sexual orientation has more to do with whom you ``fall in love'' with and feel passion towards than sexual activity -- the sex of the partner you are attracted to directs whether the behavior is homo (same sex) or hetero (other sex) sexual. As far as we know, non-human animals do not fall in love or experience passion. Their sexual behavior, which is almost entirely hormonally induced and occurs during very brief periods in most species, is linked to their fertility cycles. Sexual behavior between animals of the same sex has been found in invertebrates (fruit flies); birds (certain gulls, geese, ducks, turkeys); (domestic or held captive) mammals (bulls, cows, horses, antelopes, boars, rams, sheep, dogs, cats); and primates (stumptail macaque, pigtail macaque, rhesus monkeys, Catarrhine monkeys, Japanese macaques, Hanuman langurs, vervets, squirrel monkeys, chimpanzees, pygmy chimpanzees and mountain gorillas). Keep in mind that this is just a partial list. And that, in certain cases, scientists have only observed same-sex behavior under certain circumstances (in the wild or in captivity) and/or among only females or males of a particular species.
(Dr. Reinisch is director of the Kinsey Institute for Research in Sex, Gender and Reproduction, Indiana University-Bloomington.)
Copyright 1993, United Feature Syndicate, Inc. \enddata{text,19125256}
Here is the AAAS press release regarding the Hamer study which will appear in this week's Science. Following, is NOGLSTP's press release regarding the matter.
- - - - - PRESS RELEASE- - - - - - -
Embargoed Advance Information from Science
Release 6pm EST Thursday, 15 July 1993
Summary of "A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation," by Dean Hamer, Stella Hu, Victoria Magnuson, Nan Hu, and Angela Pattatucci at the National Cancer Institute, NIH, in Bethesda MD.
DNA markers link male homosexuality to X chromosome: Re- searchers at the National Institute of Health have used pedigree analysis and family DNA linkage studies to identify a region on the X chromosome that may be linked to sexual orientation in a selected group of homosexual males. This analysis constitutes the first step toward mapping and isolating a genetic locus which may influence sexual orientation within a certain subset of male homosexuals.
To examine the inheritance pattern of homosexuality, the authors queried 114 homosexual male volunteers about the sexual orientation of their fathers, sons, brothers, uncles, and male cousins. After assessing the reliability of this information, the authors assembled pedigree charts indicating that the men's brothers, maternal uncles, and maternal cousins had a signifi- cantly higher probability of being gay than would be expected, given the incidence of homosexuality in the general population (estimated as 2%. At the same time, fathers and paternally related relatives had rates lower than or equal to the general incidence rate.
One explanation for maternal transmission of a trait ex- pressed in males would be linkage to the X chromosome, which every male inherits form his mother. To look for a region that might contain a gene sequence that increases an individual's probability of being a homosexual, the authors used 22 DNA mark- ers to scan the X chromosomes of 40 pairs of homosexual brothers. They found that 64% of the sibling pairs tested had a cluster of five identical markers within a discrete region on the tip of the long arm of the X chromosome. This region, called Xq28, is ap- proximately 4 million base pairs long, and is large enough to contain several hundred genes. Identification of an individual gene that might predispose certain males toward homosexuality will require further linkage analysis to narrow the target chro- mosomal region or complete sequencing of the region. "Once a specific gene has been identified," say the authors, "we can find out where and when it is expressed, and how it ultimately con- tributes to development and function in homosexuals and hetero- sexuals.
- - - - -NOGLSTP PRESS RELEASE- - - - - - -
FOR IMMEDIATE RELEASE CONTACT: Rochelle Diamond
DATE: July 15, 1993 NOGLSTP Chair
Scientific Freedom and the Ethics
of a Discovered Genetic Link to Homosexuality
There have been scientific studies in the past that have suggested a possible biological origin for sexual orientation. Now, a new study published in the July 15th edition of the journal Science, Dr. Dean Hamer has suggested that at least one genetic component, and possibly more, are involved, and that the putative gene(s) is linked to the X chromosome in humans. Our reaction as gay and lesbian scientists is mixed. On the one hand, we are pleased that there is now scientific support that sexual orientation has an immutable component. On the other hand, this work raises the specter of the various possibilities of screening for such components. We, as scientists, feel that now is the time to address the ethical questions surrounding the use of such information in advance, so that the ethics may evolve with the science instead of lagging behind, as often happens.
In popular terms, Dr. Hamer and his colleagues have looked at the genetic fingerprints of the X chromosomes passed maternally from a mother to her gay sons. Each X chromosome has a unique pattern of markers and can be distinguished from one another. Dr. Hamer has found in the majority of cases with a mother and her two gay sons that the same patterned chromosome has been passed to both gay sons. This implies that the trait for homosex- uality is not random between the two chromosomes, but is in fact linked to a particular marker of one of the X chromosomes. Dr. Hamer's data in no way implies that homosexuality is linked to a single gene, on the contrary, his research has just begun to explore the likelihood that multiple genes may govern a behavioral characteristic such as sexual orientation. In such a case, genetic manipulation of the trait would be nearly impossible.
In the best of all possible worlds, diversity would be valued and this study would be strictly of scientific interest. In our present social environment, however, there are a number of pressing concerns that need to be addressed.
One advantage of finding a genetic link to sexual orientation lies mostly in the legislative and legal agenda of obtaining civil rights under current law. For example, the Supreme Court of Hawaii is currently ruling on the legality of gay marriage, not so much on the basis of sex discrimi- nation or the right to privacy, but based on the biological imperative that a genetically immutable trait would have on civil rights protection for a minority group. Dr. Hamer's data would strengthen such a case. This information also may abolish society's tendency to seek and establish blame for a person's divergent sexuality.
There are disadvantages to linking a trait to the genome. We are concerned that in the future, it may be possible to screen fetuses for genetic traits, including homosexuality allowing for termination of a pregnancy on such a basis. Adults and children could potentially be screened for military recruitment or insurance purposes. We take issue with the possibility that marriage or childbearing might be restricted to genetically desirable people. Unregulated, this genetic information has a potential for great abuse. In a larger context, the ethics of biodiversity has not been adequately explored. The possibility of screening for diseases like Huntington's chorea, diabetes, or any other genetically transmitted disorders has only recently been discussed. What has not been discussed, but for which the potential exists, is future screening for medically irrelevant traits like gender, hair color, handedness, or homosexuality.
NOGLSTP supports the formation of a commission to take up these ethical issues and their implications for public policy, in the areas of national healthcare reform, civil rights legislation, and the right to privacy. The commission should include scientists, particularly biolo- gists, medical doctors, policy makers, and ethicists. It could be support- ed by the National Institute of Health under its Human Genome Initiative or it could be commissioned by the President or Congress, in a manner similar to the AIDS Commission.
Most gays and lesbians feel that civil rights belong to all humans and that one's genetic heritage should be irrelevant. NOGLSTP believes that civil rights for all should not be predicated on biology but rather on our humanity. Many feel that studies addressing the biology of homosexuality are irrelevant to their lives. NOGLSTP supports scientific freedom and the social responsibilities that go along with its discoveries. We believe that basic research, such as Hamer's work, should be pursued in order to further our understanding of how the universe works. However, in the real world we all must be concerned about the ethical and unethical use of genetic information.
About National Organization of Gay and Lesbian Scientists and Technical Professionals, Inc.: NOGLSTP is a non-profit national organization of gay, lesbian, and bisexual people employed or interested in scientific or high technology fields. NOGLSTP's goals include dialog with professional organ- izations, disseminating information, improving its members' employment and professional environment, opposing anti-gay and anti-lesbian discrimination and stereotypes, educating the gay, scientific, and general communities, and fostering inter-city contacts among its members. For more information about NOGLSTP, write to PO Box 91803, Pasadena CA 91109, or call 818 791- 7689.
Magazine: The Journal of NIH Research
Issue: September 1993
Title: Fear And Loathing In The U.S. Military:
Psychological Explanations For Homophobia
Author: Rachel Nowak
When President Bill Clinton promised to ban the ban on gays in the U.S. military, the military became superdefensive. Claiming that "the presence of homosexuals in the force would be detrimental to good order and discipline," Colin Powell, chairman of the U.S. Joint Chiefs of Staff, opposed lifting the ban. Colonel Frederick Peck of the Marine Corps added pathos to the debate when, in May, he told a congressional hearing that his son Scott, whom he loves, should not be allowed to join the ranks of the military. Scott is gay, and he simply would not be safe in the armed forces, said the officer.
Peck's opinion gained instant credibility from two recent, highly publicized slayings. An 18-year-old U.S. Marine stands accused of fatally beating a Japanese carpenter who allegedly put an arm around him outside a bar in Japan. And a 21-year-old U.S. Navy airman apprentice is sentenced to life imprisonment for murdering a gay shipmate in an attack so ferocious that the dead man's injuries were said to resemble those suffered by airplane-crash victims.
In a July policy statement, Clinton backed down. He proposed that homosexual men and women be allowed to serve in the military only if they hide their sexual orientation. To aid them in this subterfuge, Clinton proposed that the military cease investigating active-duty personnel and questioning new recruits to determine if they are gay.
The long-standing battle over gays in the U.S. military--it dates at least to the end of World War II, when thousands of gay service men and women were summarily discharged--has not passed unnoticed by the research establishment. Rather, a small band of psychologists, psychiatrists, and sociologists have examined with increasing vigor--and rigor--the pervasiveness of anti-gay sentiment in America and the psychological factors that underlie it.
First, the researchers surveyed the territory and found--not unexpectedly--that the vast majority of Americans condemn homosexuality. Men tend to be more homophobic than women, and more homophobic about male homosexuality than lesbianism. Consequently, psychologists and psychiatrists tend to direct their attention to male homophobia toward gay men.
Among their hypotheses: Outwardly heterosexual men who harbor intense homosexual yearnings may hold the most vehemently anti-gay attitudes of all. Psychologists dub this a "defensive reaction." And, some speculate, men who hold such defensive attitudes are likely to join the military in disproportionately large numbers, drawn to the bastion of traditional masculine virtues--strength, aggression, and heterosexuality--and to authoritarian outlawing of homosexuality as a means of quelling their homoerotic impulses.
Opinions vary on whether the anti-gay sentiment that permeates the military can easily be transformed. Some psychologists argue that the military, based as it is on unquestioning submission to authority, offers the ideal environment in which to change homophobic attitudes. Others point out that defensive attitudes can be the most difficult of all to alter.
In 1988, a national telephone survey sponsored by the National Institute of Mental Health, intended primarily to gauge attitudes toward AIDS, also probed attitudes toward gay men. The survey, which used random-digit dialing to select a representative sample of American men and women, confirmed that the vast majority of the 937 participants who agreed to be interviewed (47 percent of those who were asked) find homosexuality offensive. Sixty-four percent considered homosexuality "just plain wrong." Fifty percent believed that "male homosexuals are disgusting." Confusingly, 45 percent felt that homosexuality "should not be condemned."
A demographic breakdown of survey participants, due to be reported by Gregory Herek and Eric Glunt of the University of California at Davis in the August issue of the Journal of Sex Research, reveals that politically liberal, young, highly educated, or female Americans are less likely to hold negative attitudes about homosexuals than are conservative, older, less well-educated, or male Americans.
But the strongest predictor of positive attitudes toward homosexuals was that the interviewee knew a gay man or lesbian. The correlation held across each demographic subset represented in the survey--sex, education level, age--bar one: political persuasion. Conservative men and women (but not liberals) who had had contact with gays did not differ significantly in their attitudes about homosexuals from those who never knew a gay man or lesbian.
No such in-depth studies of attitudes toward homosexuals among military personnel exist. But a widely cited Feb. 28 Los Angeles Times survey of 2346 enlisted servicemen and women concluded that 74 percent of the current members of the armed forces oppose lifting the ban on homosexuals in the military. Sixty-three percent of the 74 percent who opposed lifting the ban did so because they objected to sharing quarters with homosexual men and women. Forty percent, because they believed that homosexuality is immoral.
Homophobia, both in and out the military, bears many of the hallmarks of phobias against other minorities. For example, gays, like blacks and Jews before them, are often accused of having a predilection for child molestation--a reflection, explains Herek, of a "general cultural tendency to portray disliked minority groups as threats to the dominant society's most vulnerable members."
"Xenophobia has been characteristic of human societies, as well as lions, wolves, hyenas, and other social animals," says evolutionary biologist Jared Diamond of the University of California at Los Angeles. "Basically, it's competition for space and resources." Most psychiatrists, psychologists, and evolutionary biologists agree, however, that the evolutionary "competition-for-resources" argument does not adequately explain homophobia.
"There is something added," Diamond says. "One could speculate [that] people become outraged that someone should transgress what we have been taught, from childhood on, not to do. Maybe we are outraged that someone is doing something that all of us have felt some inclination to do at some time. The explanation is to be sought not in sociobiology, but in psychology," he says.
Sigmund Freud hypothesized that every child starts out as bisexual, then during the Oedipal stage of development (4 or 5 years old) learns to suppress sexual feelings toward the same sex. Male homosexuality occurs when this sexual development is arrested by an overly domineering mother or an absent father.
Few people still subscribe to Freud's theories about homosexuality, in part because recent evidence indicates that homosexuality can have a biological basis (see October 1992 issue, page 53, and box, page TK). But, the psychodynamic theories derived from Freud's teachings are frequently used to explain homophobia. For example, some Freudians reason that excessive hostility toward homosexuality occurs when a person with strong homosexual leanings finds his or her desires unacceptable and "projects" that self-contempt onto people who are openly or apparently gay.
Alternatively, homophobia may be a projection of individuals' insecurities about their gender identity, says Patrick Suraci, a Manhattan clinical psychologist and author of Male Sexual Armor: Erotic Fantasies and Sexual Realities of the Cop on the Beat and the Man in the Street. Gender identity denotes not biological sex, but male or female physical and psychological characteristics--in other words, how masculine or feminine a person appears. Asked to define "masculinity," the 134 New York policemen and 1,392 civilians interviewed for Male Sexual Armor "commonly responded, not being homosexual," says Suraci. The tendency of men to define gender in terms of sexual orientation may explain why more men than women are homophobic. That men tend to be more phobic about gay men than gay women could be explained by the cultural taboo against anal sex.
Finally, some psychologists speculate that the disgust some men feel toward male homosexuals is rooted in fear and hatred of women. "Gay men are often perceived as feminine [by heterosexual men]," says Richard Isay, clinical professor of psychiatry at Cornell Medical College in New York, and author of Being Homosexual: Gay Men and Their Development.
But not everyone is happy simply to invoke Freud in order to explain homophobia. "One of the problems with psychodynamic theories is that because it is not possible to observe unconscious processes directly, it becomes very difficult to test them empirically," says Herek.
Nor is that the only problem facing the study of homophobia. "To characterize the attitudes towards a particular group as being a scientific problem for study implies it is not perfectly acceptable or understandable to have these attitudes," says Herek. "That is not a scientific judgment; that's a value judgment."
Despite those misgivings, Herek has attempted to inject some objective reasoning into the study of homophobia by looking not at subconscious processes, but at the attitudes those processes create. To do this, he refashioned a 40-year-old psychological theory postulating that attitudes enable people to meet psychological needs. In a 1987 paper in the Social Psychology Quarterly, Herek contends that a homophobic attitude may meet at least three different emotional needs or, put another way, have three different functions.
The first, Herek dubs the "self-expressive function." In this case, the attitude helps meet the psychological need that people have to conform, or to define themselves according to a set of values--Christian ethics or libertarian philosophies, for example.
Thus, an anti-gay attitude may be primarily a bid for peer approval, rather than an expression of deep-felt hostility toward gay men and lesbians. Alternatively, "[for some people] being a good Christian means condemning gays. For others, being a good Christian means they must love everyone, including gays," says Herek. "A person's sense of self-esteem may be very tied up with how well they live up to those values."
The second function is termed the "experiential-schematic function." In this case, the attitude is forged by a person's tendency to organize the world on the basis of past experiences. According to Herek, "This is often considered the most rational reason for holding a particular attitude."
Finally, an attitude may serve a "defensive function," that is, give the person the means to deal with psychological conflicts that he or she cannot address directly. Thus, intense homophobic attitudes may indicate people's anxieties about their own repressed homosexual tendencies, or concerns about how masculine or feminine they consider themselves. The defensive function--which Herek calls the "methinks-thou-doth-protest-too-much function"--is firmly rooted in the traditional Freudian concept of projection.
To test his hypothesis, Herek asked 205 male and female college students who identified themselves as heterosexual to write a short essay beginning, "I have generally positive [or negative] attitudes toward lesbians and male homosexuals because ...." After scrutinizing the essays for the occurrence of 28 predetermined themes--ranging from statements about emotional reactions to homosexuality to expressions of stereotypical beliefs about homosexuals--Herek divided the students on the basis of their attitudes toward gays into the three categories. Forty percent of the respondents' answers fell exclusively into the self-expressive category, 12 percent fell exclusively into the experiential-schematic category, and 11 percent, exclusively into the defensive category. A battery of psychological tests--ranging from the Defense Mechanisms Inventory (to test defensiveness) to the Religious Ideology Scale (to test adherence to religious principles)--confirmed that the cause of the students' attitudes had been correctly categorized. Based on his results, Herek constructed the Attitude Function Inventory (AFI), a relatively rapid measure of the types of attitudes a person holds.
The test volunteers were all college students, so the findings do not necessarily reflect attitudes in society in general, says Herek. "My guess is that, in society, relatively few people would fit into the experiential-schematic category," he says. "Most [people's] attitudes [toward homosexuality] would fit the self-expressive function because that is how the society's debate on homosexism is defined."
Many psychologists believe that the pattern of attitudes in the military also differs from society's, in general. Homophobia aimed at gay men will be most prevalent in predominantly male groups such as the military, or certain sports organizations that, in the interests of the group image, require adherents to repress the feminine qualities that are traditionally associated with male homosexuality, says Isay.
Isiaah Crawford, a clinical psychologist at Loyola University of Chicago, suggests that men with strong homosexual desires who believe that homosexuality is a transgression of accepted moral standards will be attracted to the military for another reason. "The structure provides them with boundaries in which they can limit their urges," he says. In the military, homosexuality violates not only a moral standard, but a rule, too.
Herek disagrees: "In reality, people are attracted to the military for a variety of reasons--economic concerns, a desire to serve one's country, and a need to train for a career. These will be much stronger motivations [compared with the desire to suppress homosexual tendencies] for most people."
There is even less agreement on whether military homophobia can be eradicated. Herek says it can be done and refers back to the telephone-survey findings. "Even in groups that were more representative of the military--men, lower education levels, younger rather than older--the experience of contact with a openly gay person seems to result in a more positive attitude," he says.
Crawford is less optimistic. He believes that the homophobic attitudes of many military personnel are rooted in defensiveness. "Defensive reactions are generally the most difficult to change because people are not operating at a conscious level," he says. Crawford has empirical data to support that belief. He and Theresa Luhrs of De Paul University in Chicago, he tored the attitudes toward gay men and lesbians of 128 male and female heterosexual students after half of the students viewed excerpts from The Times of Harvey Milk, a documentary that challenges popular stereotypes about homosexuality.
According to the results of Crawford and Luhrs' study, due to be presented at the American Psychological Association annual meeting in Toronto Aug. 20-24, on average, the students who saw the documentary expressed more positive attitudes toward homosexuals compared to students in the control group. However, the attitudes of the subset of students that fell into the defensive-function category according to Herek's AFI were similar between the two groups.
Nonetheless, concedes Crawford, "the military is based on a hierarchal command structure, so if someone tells you to do something, you do it, regardless of how much you don't want to. That won't initially change attitudes. But over time, as people have positive experiences with [gay men and lesbians], some of those attitudes will change."
This is the angle taken by the Canadian military. When, 10 months ago, it canceled its ban on the promotion of gay men and lesbians, the Canadian forces high command made it clear that transgressions of the new policy would not be tolerated. "The way we approach it is to have everyone from the top down pass on the message and live the message that individuals are to be assessed on their performance, not on their sexual orientation," says Major Ron Dickenson, a policy analyst at the Canadian forces National Defense Headquarters in Ottawa. No reports of violence or harassment have been made so far, Dickenson says.
According to modern folklore, the U.S. military was instrumental in shaping the gay community into the political force it now has to reckon with. Many of the 9,000 gay military men and women who received dishonorable discharges at the end of World War II could not face returning to their home towns. Instead, they settled where they had disembarked--in the great port cities of New York and San Francisco, spawning two of largest gay communities in the world. Some of the gay veterans were crushed. Many were angry. That anger helped politicize the gay communities.
If the military ban on homosexuality is ever completely lifted, the U.S. armed forces may once again have a far-reaching impact on the gay community. Not only will openly gay men and lesbians be able to fight for their country--seen by many as a high honor--but lifting the ban would also sound the retreat on anti-gay discrimination in other arenas. The U.S. military is the largest, and one of the most influential, employers in the country. As San Francisco historian Allan Berube puts it, "If they let gays into the military, they can hardly rationalize keeping them out of the Boy Scouts, can they?"
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