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In Defense of the Gay Gene (and Gay Choice)

November 9, 2009 Leave a comment

The struggle for the rights of Gays, Lesbians, Bisexuals and the Transgendered have made headlines in recent days. While voters in Maine overturned a law recognizing same-sex marriage, Washington State voters upheld a law which protects legal benefits for same-sex couples.

While forward thinkers generally support the rights of gay citizens, there are those — typically on the evangelical Christian right — who believe that homosexuals should not enjoy the same rights as heterosexuals. They argue that gays choose to be the way they are, and that their lifestyles are not in teaching with Christian values. As such, they don’t deserve to be included.

Science, on the other hand, generally agrees that homosexuality is not a choice, but is genetically caused. It’s not a lifestyle, scientists would argue. Just people living their lives the way they are genetically programmed to. A careful look at the research reveals the truth to this argument.

The Studies

Geneticists and other scientists often study sets of twins to determine the role that “nature and nurture” (genetics vs. environment) play in certain conditions. Especially useful are identical twins who are raised in different households, because their genetic makeup is identical but the conditions under which they were brought up are different. By comparing data from these individuals to a baseline of other sets of siblings we can determine if there is a strong genetic correlation.

One such study was performed to determine the possible genetic influence upon homosexuality in 1991 by J. Michael Bailey and Richard Pillard. They found that in pairs of identical male twins where one twin identified as homosexual, his brother did more than 50% of the time. This is compared to 22% of fraternal twins, and 11% of adoptive siblings. To many, this lends credence to the notion that homosexuality is caused genetically.

Critics, however, were quick to point out what they perceived as flaws in the study. If identical twins are genetically identical, and homosexuality is caused by genetics, then both twins should be gay 100% of the time, their argument goes. They also point out that because homosexual couples cannot reproduce, a “gay gene” should have been weeded out by natural selection.

These arguments have persisted to this day in anti-gay circles. However, they don’t appear to stand up to serious scientific scrutiny.

The Closet

While scientists are nearly certain that homosexuality isn’t something a person can choose, we all know that a person can choose whether, when, and to whom he or she will reveal that they’re homosexual. “Coming out of the closet” is a cliche we’ve all heard. I would expect that most LGBT individuals choose to be discreet about their preferences for at least part of their life.

LGBT people in America and many other societies face prejudice and harassment, often even from close friends and family members. I imagine that it is more likely for a person to be gay but apprehensive about revealing their preference — even in a relatively anonymous study — than to be truly heterosexual but choose to endure the hardships that face homosexuals today simply so they can live a certain lifestyle. “Closeted gays” certainly outnumber “closeted straights”. Is it not unreasonable that one twin, living in a different city with a different career and different acquaintances might choose to be “out” while the other remains “in”?

Genetic Penetrance

Geneticists also understand something that anti-homosexual people apparently don’t: the concept of penetrance. Different genes carry with them different probabilities of having the affect they’re known for. In other words, if a pair of identical twins share a certain gene that is not completely penetrant, it is more or less likely that one will be affected by it but the other will not.

This is the case for certain disorders such as Type 1 Diabetes. It is well known that if one identical twin has Type 1 diabetes, the other has an approximately 50% chance of having it also. Is it not possible that the “gay gene”, like the Type 1 Diabetes gene, does not have 100% penetrance?

That would also explain how the “gay gene” could be passed on without being weeded out through natural selection. It’s highly likely that there are millions of heterosexuals walking around who have the genetic code required to be homosexual, but who have not come to be affected by it. These individuals go on to reproduce and pass that gene on to their children, who also may or may not be affected.

Does it even really matter?

The case for the “gay gene” is very strong. Anyone who doesn’t have their heads buried in the sand can see this. But for those who don’t, there is one final question: why does it matter whether it is genetically caused, or a conscious choice?

There are plenty of choices that the Bible says are wrong (and many of them are very ridiculous). Why do so many people believe that it is wrong to legally discriminate against those “sinners”, but discriminating against homosexuals is OK? People choose to be Muslims, Jews, Pagans. Some people choose to be atheists. All of these are “wrong” to evangelical Christians. Should we make a law outlawing their organizations? Should we say that Muslims, Jews, Pagans and atheists can’t marry each other?  Of course not. Nobody would agree to that. But why, then, do so many people believe that a man shouldn’t legally be allowed to marry another man, or a woman marry another woman?

Furthermore, and oddly enough, many of the same people who support anti-gay legislation are the type who object to all sorts of other laws on the grounds that they are “big government”. In other words, it’s wrong for “big government” to try and influence the economy or protect the public’s safety. But it’s OK for “big government” to pry into your family and your bedroom? That’s seems very illogical to me.

I’m fully convinced that homosexuality is caused by a genetic variation. Hopefully by now you would agree. Maybe you don’t. But even if it is a choice, shouldn’t people be allowed to make that choice without being discriminated against?

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