Monday, 18 November 2013

Identical twin studies do not show homosexuality is not genetic (and it does not matter anyway)

Note: I had forgotten about this, but its still relevant

Pseudo-science is my pet peeve. Its the most horrible thing as it can get used by fundamentalists all the time to twist truth about real valid scientific studies as was done earlier this years by The American Vision in an article titled "New Twin Study: People Not Born Gay" This stems from another article on the Holland Davis Christianity website which has to do with ideas of a Dr. Neil Whitehead.

What does this doctor have to say, well apparently:
Eight major studies of identical twins in Australia, the U.S., and Scandinavia during the last two decades all arrive at the same conclusion: gays were not born that way.
Yet there are only two citations for these studies. The main citation to the Bearman and Bruckner study which does not suggest genetic variation as a main cause but does not eliminate it, you can read the article here. Interestingly,the Bearman study deals with opposite sex twins,so even if they are identical they have one whole chromosome that is different. The Bailey study which is also cited suggests genetic variation, read here. So I am not sure how Whitehead is doing this, I mean birth studies say that he cites by name are saying there is a genetic component. But that is irrelevant really, as the more important issue comes next.

He also says that:
“Because they have identical DNA, it ought to be 100%,” Dr. Whitehead notes. But the studies reveal something else. “If an identical twin has same-sex attraction the chances the co-twin has it are only about 11% for men and 14% for women.”
and
"Because identical twins are always genetically identical, homosexuality cannot be genetically dictated. “No-one is born gay,” he notes. “The predominant things that create homosexuality in one identical twin and not in the other have to be post-birth factors.”"
Except that this is not always the case, as minor things can cause mutations. So in effect the DNA of identical twins is not 100% as the doctor claims, as the doctor does no understand the concept of mutation. So how can any study make claims using identical twins when they have no specific gene to pinpoint? Hint: They cant. Especially when the Beraman study he likes to claim shows there is no link specifically states:
"The first model,the idea that homosexuality is a polygenetic trait cannot be tested with our data."
In fact the authors are very cautious to completely discard a genetic link. Also although this study is a big study it is important to note that only 289 of the 3,139 pairs of siblings were actually identical twins in this study. And by identical I mean that one was a girl and one was a boy but they came from the same zygote.

The problem is that this Dr Whitehead is using helpful research to support fundamentalist ideas. He is using science to support pseudo-science and it is unethical. This guy is an idiot who does not understand biology, and for that matter is not a medical doctor. His PhD is in biochemistry and statistics, so next time you comment Dr Whitehead, make sure its something you apply rational thinking to.

BTW, it does not matter if homosexuality is genetic or not. People are free to do what they want, and if you are homophobic you are an idiot. Stop using your religion to hide behind. Homophobia is wrong, stand up and show you are a bigot but stop hiding behind fairy tales.
New Twin Study: People Not Born Gay
New Twin Study: People Not Born Gay
New Twin Study: People Not Born Gay