Just forget, for one brief moment, the politics currently revolving around homosexualty. Also forget, for a moment, about any moral issues you associate with the matter, either way.

Since it affects so many, it's important to understand how same-sex attraction comes about. Is it genetic? Is it a product of environment? Some combination? Is there such a thing as volition or free will? Our thinking should be influenced by scientific evidence; we should look carefully to see how reliable it is, and, if so, what it has to say to us.

Instead, it seems many people, and particularly the press, have already chosen the correct "scientific" answer in advance. Any apparently confirming evidence -- no matter how weak or specious -- is trumpeted loudly while disconfirming evidence -- no matter how strong -- is ignored or swept under the rug.

Remember we were all told there was a "gay gene"? Study after study has revealed there was no truth whatsoever to that "scientific assertion." Yet many people are walking around convinced that we know homosexuality is genetic, despite the fact that their view is unsupported -- indeed, even contradicted -- by science. You might as well ask them if evil eye can be cured with a poultice.

New 'Gay Gene' Study

Case in point: Recently, yet another study looking into the "gay gene" theory came up empty: Nope, there's no gay gene.

So how did the media report this?

The BBC, for example, chose a headline which implied the opposite: "Non-sex genes 'link to gay trait'". The researchers, after finding there was no gay gene, speculated that gayness might be stored among several genes and speculated on some specific genes that might be related. This speculation, and some rather weak evidence (in a moment) formed the basis for the headline. The strong evidence, that there were no genetic sequences found in common among gays, was downplayed.

The only bit of purported evidence the BBC offered in support of the aformentioned speculation was that, in a study of gay brothers, "[a]bout 60% of these brothers shared identical DNA on three chromosomes." Perhaps to make the reader think this is significant, the BBC assures them "only 50% of these stretches [of DNA] would be shared" by chance.

But is this statistically significant?

Even if were, it would not prove sexual orientation was a genetic "trait": It would show that gay brothers sometimes shared some DNA with each other -- not that gay men from different families share common DNA.

That would hardly be suprising, given that they've already selected for a given common behavior. Consider: It takes intelligence to be a chemist. If we examined the DNA of brothers who were both chemists, they'd likely share some DNA for intelligence. Would that mean being a chemist was a 'genetic trait?' Of course not. A "trait" is an unchangeable characteristic influenced predominantly by genes, not by environment. "Chemist" fails on two counts, even if chemist-brothers would be found to often share DNA.

And since the gay brothers were undoubtedly raised in the same family environment, it's meaningful to note that are no controls to sort out how much was nature, and how much was due to their common nurture.

But it gets worse, still: What the BBC does not tell the reader directly is that the 60% correlation was, in fact, not statistically significant. The observed variation from random chance -- 10% -- is not meaningful in a sample as small as the one they used. Yet the chosen language leads the reader to draw a scientifically invalid conclusion.

This deception is confirmed here and also can be inferred later in the article, where the researchers admit the above evidence didn't prove their case:

"Sexual orientation is a complex trait. There is no one 'gay' gene. Our best guess is that multiple genes, potentially interacting with environmental influences, explain differences in sexual orientation."

You can also see the researcher's own bias here. His choice of words clearly assumes that sexual orientation must be a genetic "trait"; no other possibility is entertained. He is trying to explain how that can still be so in the face of disconfirming evidence. The answer has been chosen in advance, now we must find the data to "prove" it. Forget about your cherished view of homosexuality, whatever that might be: This is, frankly, very bad science.

Actually, it's probably even worse, still, than even the link above reports: It looks to me as though they examined many different genes, and then only reported those where high numbers were found after the fact. This is a notoriously deceptive technique called "cherry picking", and is the worst kind of "science" which can be done.

So, here's a hilarious story: Researches with a stated pre-exisiting bias do an experiment which ends up disproving the theory of the 'gay gene'. So they instead look for matches among a wide set of genes, and only report those where the correlation was found to be high, implying it's a significant finding, when it isn't, and implying it proves something which it wouldn't anyway. The media then distorts this further, downplaying the setback and making the speculation sound stronger than it is.

Amazing!

Reactions

Of course, there's no shortage of readers eager to hear their pet theories confirmed. Among those who strained out the factual camels to feast upon speculative gnats was Libertarian Girl, who took the BBC's distortion one step further. Whereas the BBC asserted deceptively there was a "link" to genes, LG cites the article stating, falsely: "There is now scientific proof that gayness is a hereditary trait."

Apparently LG can't tell the difference between a statement based in the researcher's feelings and evidence -- even when coupled with a direct, honest admission the researcher hasn't located the proof yet.

There are numerous other hilarious errors, leaps of logic, and stereotypes in her article. She upbraids another blogger for having "missed the point" for thinking the article disproved the gay gene theory. In fact, he was standing on solid ground and correctly seeing the real finding, where she was falling for the BBC's spin about the researcher's admitted "best guess."

She also asserts, "the gay person usually won't reproduce". How often is "usually"? Is she completely unaware of Kinsey's finding that the vast majority of self-identified "gay" men he studied had heterosexual sex in the last five years? Ever hear of Gene Robinson, gay bishop? He has two children. Governor McGreevy?

Among those I know who have at one point had or have a homosexual lifestyle, many of them have children, including even one of the men who came to the door to talk about the importance of gay marriage. Gay.com makes a similar point, saying, "We all know many gay people have children from previous marriages," As does this gay-positive FAQ which states: "Sexual orientation does not seem to preclude the desire to breed... it is no surprise that homosexuals can, do, and always have had children."

Then she makes an even more fantastic leap to this idea: "having some of these gay genes must have caused a person to have more children." Really! Beyond the missing evidence for gay genes at all, where is the evidence they are linked to increased fertility?

Childhood diabetes, for example, is hereditary. Since its sufferers, until very recently, would have died before achieving adulthood, it must have "died out" unless it caused higher fertility, no? So where is the evidence diabetics are more fertile?

This is a silly kind of reasoning which ignores the basics a 9th grader is taught about reproduction: Some anti-reproductive genes, such as diabetes and sickle cell anemia, are passed along because they are recessive.

And we also learn that "fashion sense" is both absolute and stems from DNA somewhere on chomosomes 7, 8, and 10 -- the ones suspected in the article: "better fashion sense is one of the positive benefits of at least one of the genes correlated with gayness." I won't even go into the fact that some of gay men I know are terrible dressers. Just because a number of top designers are gay doesn't mean the reverse is true.

And, sadly, she still seems to be misinterpreting the study: It claimed that gay brothers shared DNA with each other, only -- not that some set of genes were found to be common among gays from different families. No common genes were identified. The researchers only suggested several chromosonal areas might be related -- not that they'd identified specific DNA configurations ("genes") which led to homosexuality.

And we also learn this: "This fashion sense probably stems from the gay man's innate superior ability in sythesizing complicated social cues." Ah yes, gays are mostly emotionally sensitive types -- there are no butch or "bear" he-man gays. And of course emotional sensitivity or social adroitness must translate directly into a strong visual sense of aethetics! (Yet some of the best artists were completely socially inept -- Van Gogh, for example!) Once again, where's the evidence for these amazing leaps?

Stereotype, stereotype, stereotype. All in the context of a 'scientific' discussion!

This is critical thought?

Related Thoughts

I'm open to the idea that homosexuality may have a genetic component, like much else in life. But as far as being an immutable genetically-based trait, I'm skeptical, since that doesn't match the evidence I see in real life.

We all know gays who remember feeling sexual attraction fo the same gender early in life. But there are at least two problems with using this as evidence that homosexuality is genetic.

(1) In contrast, I also know people who have drifted in and out of the lifestyle. I've seen numerous people go from having heterosexual feelings and desires to engaging in a gay or lesbian lifestyle. And I've also seen the reverse, despite the current fashionable dogma that it can't happen. And while some seem to have a fixed sexual preference, others demonstrate it can change. Thus it seems foolish to base your view of a group on what is true of only a fraction.

(2) Even if one has memories, say, at age six, of same-sex attraction, this is not proof that nature was more important than nurture. Quite a lot of the personality is formed and moulded in the first several years of experience. (For example, we are learning effects of mothers not bonding with their children.) Just because something is true at age six does not prove there could be no prior environmental influences -- it's simply faulty reasoning to leap to that conclusion.

And if homosexuality is genetic, then what about bisexuality? And pedophilia? (Most pedophiles didn't choose to be as they are, and they're very difficult to change.) How about necrophilia? Exhibitionism? Is there is a gene or combination of genes somewhere coding for shoe fetishes and some girls' desires for much older men? Or, if these atypical sexual attractions could be due to nurture or trauma, then why not homosexual attraction?

We're creating neat, artificial categories where they don't exist.

My guess is that some try to distort the science here because they feel if homosexuality is genetic, then (a) it will be viewed as a positive thing, and (b) that will help protect gays from persecution. Of course, not all genetic things are positive -- diabetes and Tay-Sach's disease to name a few. And it's wrong to make the science show something for a political end -- you're basicly saying good things can be achieved through lies. I don't buy into that kind of reasoning.

Finally, here's an interesting article about a distinguished psychiatrist who claims that the idea of a fixed, inherant sexual orientation is a fiction. I do not know if everything he claims is correct (though I find some of what he says persuasive, and consistent with my own observations about homosexuality often correlating with trauma), but since the media never presents the other side of the argument, someone has to.

The idea that homosexuality is often linked to trauma might also help explain why homosexuals have a shorter life expectancy, even when AIDS is factored out. Childhood trauma increases all kinds of negative behavior in later years, such as drug use, suicide, promiscuity, crime. I see no prima facia reason to exclude consideration of homosexuality from that constellation of potential effects.

If homosexuality is genetic, then so be it. But if it's linked to trauma, and is just one symptom among so many, then we may be doing homosexuals a tremendous disservice by simply ignoring, or even glorifying what may be one of their primary symptoms, instead of attempting to understand and find ways to help them deal with the underlying damage.

Distorting the science is no way to move this important area of study forward.

Update: Ha! It turns out "Libertarian Girl" is just another arrogant atheist guy. Well, you can clearly see the special, deferential treatment I gave "her" above because of "her" purported good looks.

He says he is a talented writer. No, you wrote some of the stupidest things I'd read outside of Democratic Underground, and that's why you drew my fire. I'm enormously sympathetic to libertarian positions, but I can't stand arrogance when coupled with such willfull stupidity and disdain for evidence.

(Including my own, some days.)

He implies people only pick beliefs on utility (trust that he at least means himself by this -- that's no surprise, given his many logic errors) and says a beautiful woman would never be an outspoken, intelligent (as we are to surely agree he was) popular libertarian (though sometimes he leaves that off) blogger, but instead would be a conforming, promiscuous, moderate leftist. (So he's a sexist too. Again, shock me.)

Yeah, tell that to Moxie and Michelle, not to mention libertarian Megan McArdle ("Jane Galt"), whose blog I frequented long before I found out she was cute. Turns out these women have no talent at all -- they're just vapid, pretty faces who got ahead that way. Not to mention Baldiocks, who draws her readership by shamelessly exploiting her femininity.

But, once again, this guy's conclusions are clearly unencumbered by small obstacles like contrary evidence.