Tracking a genetic link to sexuality

Geneticist Dean Hamer says he never chose to be attracted to men. As we talked inside the renovated Washington, D.C., townhouse he shares with his partner and two dogs, the scientist popularly associated with so-called "gay genes" told me he knew he was gay since he was about 5.

That's what partly motivated Hamer, 54, to switch from basic molecular genetics to studying sexual orientation in 1992. When he told his colleagues at the National Cancer Institute what he was doing, they were puzzled. "It was pretty far out there," he says. Others thought the answer was too obvious - that of course it was genetic.

But outside the scientific community, Hamer says, it's still widely believed that gay people somehow choose their orientation and this further fuels discrimination. (Bush was asked in the presidential debates whether being gay was a choice. He said he didn't know.)

But will studying sexual orientation fight hatred or give it new tools? If scientists identify a "gay gene," will expectant parents use it for selective abortion?

"That scares some straight people away from studying this," says Hamer. "They're afraid of offending someone or causing harm." Most of the leaders in the field are gay, he said, for the same reason female researchers dominate the study of sex differences in the brain.

That limits study of what he considers to be one of the most important aspects of biology and human health. "We have the worst epidemic out there since the plague," he says. "It's spread by sex." Hamer said he was inspired to switch his focus by several studies in the late 1980s, especially one that looked at twins - a standard genetics technique.

If a trait is shared more often by identical twins than by fraternal twins it means there's some genetic component. For men, if one identical twin is gay there's about a 50 percent chance the other will be too. That falls to about 20 percent if they're fraternal. For women, the story is more complicated though science shows biology matters there, too.

Hamer realized he might be able to use the tools of molecular genetics to isolate specific genes. He studied 40 pairs of gay brothers and found a particular marker on the X chromosome that was shared more often when both brothers were gay. When he published his result in 1993 it became known as the "gay gene", but he said this label oversimplified the science. Many straight people have the "gay" version of the marker.

Scientists now know sexual orientation can't be detected from testing any single gene - it's set by a complicated combination of genes and environmental factors.

Only a few studies attempted to replicate Hamer's finding. It remains unresolved. Hamer said other gene findings are followed by hundreds of follow-up studies but the gay gene is not popular subject matter.

Neuroscientist Charles Wysocki and his colleagues at the Monell Chemical Senses Institute investigated the way male body odor caused spikes in women's hormones. They found the effect only in straight women but not lesbians. Intrigued, he followed up with a study suggesting sexual orientation influences not only how you react to the scents of others but how you yourself smell.

Other startling insights have come from studies of animals. By altering a single gene in fruit flies, researchers in Austria created males who courted and tried to mate with males, females with females. And in Oregon, researchers are finding brain differences between straight and exclusively gay rams.

Scientists say it's next to impossible to get federal funding to research anything related to sex, and especially homosexuality. And yet our political and cultural debates often hinge on such issues. Should we allow gay marriage? How do we prevent HIV? How do we educate our children so they don't contract and spread this epidemic? How can we deal with anti-gay discrimination?

Science may not have all the answers, but if given the chance, it could at least inform these debates.

But outside the scientific community, Hamer says, it's still widely believed that gay people somehow choose their orientation and this further fuels discrimination.

Further fuels discrimination??? What a load of crap. The real reason this man does this is to fuel the we-hate-being-called-for-what-we-are crowd. Gays seek nothing more than legitimization for their actions in all ways possible. They are on average more affluent, educated and traveled than the general populace, are less than 2-3% of the population but CONTROL more politicians than any sub group except for the AARP types. They seek legitimization by infiltration of all churches to make gay pastors and priests simply to be able to say "See, even the Church of XXXXXX says were normal."

In this process they tear down societal norms, destroy rights of association guaranteed under the constitution and claim discrimination to a greater degree than do Blacks or Women and yet have not one shred of peer reviewed, valid and convincing study that supports their genetic predisposition claims. Its always a "gay researcher" who comes up with the next great study.

Look at the recent film out in the theaters. Gays and gay supporters laud this movie as some new high water mark in society all the while failing to show the film for what it does...legitimizes an adulterous affair of two me who while married and with families cheat on their wives with each other. Oh, that is such a wonderful thing to do in the name of your so-called "sexual orientation." Their sky-is-falling rant and raving about how oppressed they are falls on mostly deaf ears because it is built on a mountain of lies. Making claims to being born that way while denying those who have LEFT homosexuality shows their willful desire to do nothing more than make it acceptable.

But outside the scientific community, Hamer says, it's still widely believed that gay people somehow choose their orientation and this further fuels discrimination.

Those of us "outside the scientific community" think this because real life provides many such examples that contradict the "gay gene" theory. People don't buy "it's all genes, never choice" when they observe things like the "lesbian until graduation" phenomenon at certain colleges. They don't buy it when they see lesbianism and bisexuality becoming ever more popular with college age women. Have our genes suddenly changed that quickly? They don't buy it when they observe (like I have) identical twins, one gay the other straight. How can genes alone cause this? They don't buy it when they read history and learn how, for a certain period, the upper class men of Athens all preferred to have sex with boys. Did they all just get the gay gene while few of the lower class men in the same city had the same gene? And so on.

The situation just isn't that cut and dried. I imagine that homosexual orientation is a result of a combination of genes and environment and has many different causes which vary from person to person. I don't think very many people consciously choose to have same-sex attractions, but I do think some people are exposed to environmental factors that lead to them becoming gay unconsciously. Perhaps if these factors had not been present, these people would not have SSA. In other cases some people might be physically and genetically constituted in such a way that they will turn out gay no matter what environment they are raised in. We just don't know.

Discovering the cause or causes of SSA doesn't affect arguments concerning the morality of it one way or another. Those who have no moral qualms with gay sex can't justify this stance by saying "it's all genetic." So what? Having a genetic or innate disposition towards something doesn't mean the behavior is necessarily moral or immoral. Just because things are a certain way doesn't mean they ought to be this way.

Likewise those who hold that gay sex is immoral shouldn't have a problem if it turns out SSA is totally genetic. Genes do not equal morality. All the discovery of a gay gene would show is that some people have a genetic tendency to desire to engage in immoral behavior. This is probabably the case for other immoral behaviors too, like addiction. So what? People can still choose to act on their desires or not act on them. That's where the real moral concerns come in. I don't think many conservatives think it is morally wrong simply to have a gay orientation - it's when people choose to act on it and promote such behavior that conservatives get upset.

Geneticist Dean Hamer says he never chose to be attracted to men.

Implied Premise: Sexual orientation (further implied homosexual behavior) is a trait you are born with, like hair color…

Counter argument: Fact: Heterosexually oriented adults exist who choose for religious reasons to be celibate. Obviously, adults have the power to choose to be celibate. Therefore, sexual orientation is irrelevant to the choice to engage in sexual activity whether it is heterosexual or homosexual. In other words, regardless of whether or not someone is “BORN homosexual” (a point which I do not grant), their voluntary choices determine their behavior (i.e., “being celibate, or not).

Science may not have all the answers, but if given the chance, it could at least inform these debates.

Counter argument: Fact: Procreation (without extraordinary scientific intervention, i.e., in-vitro fertilization, etc.) is impossible to exclusively homosexual behavior practitioners. Therefore, unless homosexuality is a genetic anomaly (mutation or defect), the owners of this trait would completely disappear from the population in a few generations or less.

Counter argument: Fact: Genetic anomalies which preclude their victims from reproducing appear in the population at the sum total rate of less than 0.5%, according to the Centers for Disease Control (CDC). Therefore, if homosexuality were a genetic anomaly (i.e., an inborn trait resulting from a mutation, defect, etc.), it would appear in the population at much lower incidence than is observed (something between 1%-10%). Therefore, it is a logical conclusion that all but 0.5% of homosexuals (at most) behave as such out of choice.

Counter argument: Fact: Homosexual behaviors observed (B.F. Skinner, et al) in non-human animals are neurotic, abnormal singularities and require artificial, forced conditions (e.g., overcrowding) and are never seen in the normal habitat and behavior of these animals. Therefore, homosexual behavior in animals and, by extended implication, in humans, is not an inborn trait but a behavioral response to an environmental condition or situation resulting in a neurosis. In the case of humans, all behavioral responses including neuroses that are not pathological psychoses are voluntary and controllable.

Conclusion: Homosexual behavior is an individual choice, i.e., a voluntary behavior regardless of the existence of a genetic predisposition or lack of such. Since all voluntary behavior is subject to prohibition or other regulation by law at the behest of the majority of the governed, homosexuality is as much subject to legal prohibition as is rape, incest, bestiality, etc.

Geneticist Dean Hamer says he never chose to be attracted to men.

Implied Premise: Sexual orientation (further implied homosexual behavior) is a trait you are born with, like hair color...

Counter argument: Fact: Heterosexually oriented adults exist who choose for religious reasons to be celibate. Obviously, adults have the power to choose to be celibate. Therefore, sexual orientation is irrelevant to the choice to engage in sexual activity whether it is heterosexual or homosexual. In other words, regardless of whether or not someone is “BORN homosexual” (a point which I do not grant), their voluntary choices determine their behavior (i.e., “being celibate, or not).

But: Virtually ALL phentypes (observable characters of humans or other organisms) are ultimately the product of an interaction between genes and environment. In some cases, an environmental component may be minor, in others genetics may be minor. This a problem when scientist (in the interests of simplicity) calls a gene the "gene for X". What a gene for X really corresponds to is a gene that has at least alleles (forms) that shows a detectable impact upon a phenotype when that one of those forms is present in one (for dominant phenotypes) or two (for recessive phenotypes) copies.

Personally, I find some of Hamer's work on genetics and faith to be poorly supported, though I have only scanned his book. His "gay gene" work seemed reasonably solid. I read the original paper when it came out and it was a solid linkage study, though those sorts of studies only localize variant forms of a gene to a large section of a chromosome, potentially including multiple genes that contribute to a phenotype.

Science may not have all the answers, but if given the chance, it could at least inform these debates.

I didn't see anyting in your counter-arguments that actually took issue with the statement above, which I find perfectly reasonable. By definintion science can't have ALL of the answers. But anybody who igornes it completely is not connected to reality. Before jumping on my case, note that all I'm saying is science should never be ignored completely - how much weight it should be given relative to other considerations is an open matter that I think we all expect to see different folks having different opinions on.

Regarding the other arguments:

1. Homosexual individuals are only incapable of reproduction if they are exclusively homosexual. That is not the case and was probably even less the case during periods of history where men were expected for social reasons to marry and carry on the bloodline. Even in America, many gay men probably married during the '50 simply because being gay was not acceptable.

2. There are two reasons why a gay gene would persist in a population:

a. mutation-selection balance - the removal of genes from the population is balanced by novel mutant alleles. For reasons I won't go into, this typically involves the generation of recessive alleles of a (physically) large gene. This is unlikely to be the explanation, since it cannot explain the large proportion of homosexuals in the population unless different assumption are made.

b. sexually-antagonistic genes - genes that increase the fitness of one sex while reducing the fitness of the other are very well characterized (think of the train in peafowl - peahens definitely select males on the basis of their train, but it increases the impact of predation on peacocks). In the case of a gene for male homosexuality the allele conferring a homosexual phenotype would have to have a DIFFERENT phenotype in females. I think a study in Proc Roy Soc London (a scientific journal) provided evidence for this that was suggestive but not conclusive (my memory could be fading me - I remember this from scanning abstracts). I suspect this is the case.

I would add that both of these compatible with evolutionary theory, and the existence of sexually-antagonistic genes has been hypothesized to have a specific impact on the evolution of sex chromosomes. Genome projects have confirmed those predictions - mammalian sex chromosomes look the way you would predict from theory, and completion of the chicken sex chromosomes should provide a second test.

I would read something more recent than Skinner, who died 15 years ago. Off the top of my head, I know Joan Roughgarden has a popular book, though she does have the potential for an agenda. But there is a bigger problem: the naturalistic fallacy - does the way things ARE determine how they SHOULD be? I would say no. Imagine if somebody invented a drug that doubled our lifespan (and kept up healty - so we could live to 150 years of age and be able to work and enjoy ourselve for most of that). That is not natural! But how many would say it was evil because it is not natural? (a few would, but I suspect most of us would be lining up for the shot)

So, even if all of your facts were absolutely correct, that would simply say how things are, not how they SHOULD BE. Likewise, if half the population were born with a homosexual orientation, it would be exactly the same.

I support full gay rights for a philosophical reason - that of equal treatment. I am straight but I really don't CARE if somebody else is gay. Being promiscuous is probably a bad idea whether you are straight or gay, and if you are promiscuous you should always use condoms with strangers. But that is a PUBLIC HEALTH issue. It doesn't address the big issue of whether folks should have the right to do what they want sexually, as long as only adults are involved and everybody has given consent.

Ultimately, EVERYTHING is (potentially) subject to legal prohibition. The question is, what is wise for the government to prohibit. Even if I personally supported sodomy laws (which I don't) I would much rather have the cops out catching folks who assualt, rob, rape, etc. than having them catch folks engagin' in sodomy (assuming they are doin' the sodomy behind closed doors).

Article said: Geneticist Dean Hamer says he never chose to be attracted to men.

Lucky Dog said: Implied Premise: Sexual orientation (further implied homosexual behavior) is a trait you are born with, like hair color...

Lucky Dog further said: Counter argument: Fact: Heterosexually oriented adults exist who choose for religious reasons to be celibate. Obviously, adults have the power to choose to be celibate. Therefore, sexual orientation is irrelevant to the choice to engage in sexual activity whether it is heterosexual or homosexual. In other words, regardless of whether or not someone is “BORN homosexual” (a point which I do not grant), their voluntary choices determine their behavior (i.e., “being celibate, or not).

edward_geneticist said: But: Virtually ALL phentypes (observable characters of humans or other organisms) are ultimately the product of an interaction between genes and environment. In some cases, an environmental component may be minor, in others genetics may be minor. This a problem when scientist (in the interests of simplicity) calls a gene the "gene for X". What a gene for X really corresponds to is a gene that has at least alleles (forms) that shows a detectable impact upon a phenotype when that one of those forms is present in one (for dominant phenotypes) or two (for recessive phenotypes) copies.

Personally, I find some of Hamer's work on genetics and faith to be poorly supported, though I have only scanned his book. His "gay gene" work seemed reasonably solid. I read the original paper when it came out and it was a solid linkage study, though those sorts of studies only localize variant forms of a gene to a large section of a chromosome, potentially including multiple genes that contribute to a phenotype.

Lucky Dog responds: Your discussion seems quite erudite. Nonetheless, it is irrelevant to my point. That point succinctly stated is simply that the existence, or lack thereof, of a “gay” or “homosexual” gene as it may, or may not, influence sexual orientation is completely immaterial to any discussion concerning homosexual behavior.

I cited an example of a heterosexual remaining celibate as an instance where there obviously exists a genetic predisposition to procreate but that voluntary behavior “trumps” such genetic predisposition. The obvious conclusion is that no one is “required” to act on non-pathological, genetically influenced predispositions

Article said: Science may not have all the answers, but if given the chance, it could at least inform these debates.

edward_geneticist said: I didn't see anyting in your counter-arguments that actually took issue with the statement above, which I find perfectly reasonable. By definintion science can't have ALL of the answers. But anybody who igornes it completely is not connected to reality. Before jumping on my case, note that all I'm saying is science should never be ignored completely - how much weight it should be given relative to other considerations is an open matter that I think we all expect to see different folks having different opinions on. [emphasis mine]

Lucky Dog responds: I cannot challenge your argument (emphasized) above, nor would I. However, my point concerning the issue is that regardless of how or what science may inform concerning genetics and homosexual behavior, the logic of the situation is irrefutable.

edward_geneticist said: Regarding the other arguments:

1. Homosexual individuals are only incapable of reproduction if they are exclusively homosexual. That is not the case and was probably even less the case during periods of history…

Lucky Dog responds: Logically, this (emphasized text) statement reinforces my contention that homosexual behavior is purely voluntary. By weight of reason, if a homosexual can choose to engage in heterosexual activity purely to avoid stigma, then said homosexual can similarly choose not to engage in homosexual behavior. Again, the argument reduces to a matter of voluntary choice on the part of homosexual practitioners.

edward_geneticist said: 2. There are two reasons why a gay gene would persist in a population:

Lucky Dog responds: Please permit me to disregard this portion of your previous post as it is irrelevant to my point that homosexual behavior is purely voluntary.

edward_geneticist said: I support full gay rights for a philosophical reason - that of equal treatment. I am straight but I really don't CARE if somebody else is gay. Being promiscuous is probably a bad idea whether you are straight or gay, and if you are promiscuous you should always use condoms with strangers. But that is a PUBLIC HEALTH issue. It doesn't address the big issue of whether folks should have the right to do what they want sexually, as long as only adults are involved and everybody has given consent.

Lucky Dog responds: Your postulate is the “libertarian” assertion. Based upon your assertion, there is logically no such thing as “gay rights” unless you are willing concede there are rights to incest, polygamy, etc.

edward_geneticist said: Ultimately, EVERYTHING is (potentially) subject to legal prohibition. The question is, what is wise for the government to prohibit.

Lucky Dog responds: You have correctly summarized the most important issue. (Note that it is not the existence or lack of a homosexual gene.) Society has a vested interest in promoting and protecting behaviors that contribute to the good order and continuation of society.

edward_geneticist said: Even if I personally supported sodomy laws (which I don't) I would much rather have the cops out catching folks who assualt, rob, rape, etc. than having them catch folks engagin' in sodomy (assuming they are doin' the sodomy behind closed doors).

Lucky Dog responds: If sodomites only engaged in their activities behind only closed doors and did not demand “rights’ for so doing, your position might be considered by some to be tenable. However, this not the case. Currently, sodomites are demanding “gay marriage” rights with intent of weakening traditional marriage, pedophilia rights (NAMBLA), and a host of other societally destructive allowances. Consequently, your argument fails.

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