You're born gay, and that's that according to QMUL's Dr. Rahman
Dr. Qazi Rahman Queen Mary University of London's assistant professor in Cognitive Biology whose research interests include Cognitive Biology and the Psycho-biology of human sexual orientation, claims in Gay by nature: Part one: you're born gay, and that's that.
Dr. Rahman explains the impact of genes and hormones on homosexuality. Dr. Rahman views the nature vs. nurture debate as pointless, dispels the myths promoted by religious propagandists that sexuality is changeable, explains misunderstandings surrounding 'natural selection', discusses the 'Big Brother Effect', and holds mainstream media accountable for doing little to raise public understanding about the issue.
While almost all scientists accept homosexuality has purely natural causes, the debate has been mired in confusion. There have been conflicting reports about the existence of ‘gay’ genes and their significance. Religious propagandists have tried to promote the myths that sexuality is changeable. And the mainstream media, more interested in causing controversy than holding rational debate, has done little to raise public understanding about the issue. For Dr Rahman, who heads QMUL’s Biological and Experimental Psychology Group, it is quite clear: you’re born gay, and that’s that.
"The whole nature-nurture debate is entirely pointless,” he says. “Sexual orientation is not a choice because humans come in two types: one with a vagina, the other with a penis, so sexual orientation is entirely biological.
"We all end up at the same point: heterosexuality or homosexuality. There is little variation in between but this is not to exclude bisexual behaviour. People do not end up sexually attracted to bananas or animals for example. This is not a flippant comment. What I am saying is that we see the same characteristic traits and behaviours, resulting from a relatively small number of factors.
"We think the causes for different sexual orientations cluster around two areas. We know that just under half the variation in sexual orientation is down to genes. Then the rest of the variation is down to ‘non-shared’ factors, and those, like hormones, are primarily biological.”
Speaking to the question 'if homosexuality were inherited, wouldn't the genes for it disappear because of natural selection?' Dr. Rahman said:
“That is a common misunderstanding, and that is said by people with no understanding of evolutionary biology. Sexuality is a complex human trait, just like IQ or personality. It is determined not by a single gene, but how several genes work together. A whole range of features with reproductive disadvantages can be maintained in the gene pool down the generations, if only a portion of the genes responsible are advantageous to heterosexual carriers."
He continued: "One of the ideas is that heterosexual men that may carry some ‘gay’ alleles that result in more empathic and nurturing traits, which are thus more attractive to females, who might mate with them and then carry those genes on further. So long as passing on some versions of those genes is reproductively advantageous, the fact that at some point down the generations you end up with a completely homosexual male – with all gay genes activated – is inconsequential. Evolution will happily tolerate that as long as the general reproductive advantage for individuals is maintained.
"However," he added, "there is much work to do. We don’t yet know how this works. A couple of papers published last year suggested females, rather than males, benefited. Genes responsible for homosexuality have to do something, but they do not literally write the word ‘gay’ in the brain.
Explaining the hormonal influence on sexuality, Dr. Rahman continued:
"The level of exposure to sex hormones, such as testosterone, during life in the womb, seems to influence the direction of sexual preference. Everyone would be born female if it were not for testosterone. At stages during pregnancy, the hormone is introduced into the womb. The level of testosterone to which the foetus is exposed determines the level of masculinity. Some bodily markers provide an insight into exposure. One example is the relative length of index finger to ring finger.
"There are a whole range of measures like startle responses, a particular sound emission that comes from the inner ear and cognitive profiles, which show how people perform on different problem solving tasks."
So, are the brains of homosexuals wired differently? The 'Big Brother Effect':
"In males the big brother effect is also important. Gay men tend to be born younger in relation to their brothers. The maternal immune system recognises successive male foetuses and may form an immune response to particular types of protein that form on the surface of the brain in the developing foetus. This might affect sexual differentiation or it might produce some hormonal mechanism that produces that variation, too. The big brother effect only appears to be important when gay men are right handed. Left handed gay men owe their sexual orientation to other causes we are unaware of.
"Relatively recently, there has been lots of research into neurobiology – what goes on in the brain. Our lab has been working a lot on mental problem solving skills like spatial ability, finding your way around, finding important objects in a spatial environment, emotional skills and verbal recognition.
"And we know these are different between the sexes, but we find gay men tend to have a female type of spatial ability. Spatial ability is controlled partly by two regions of the brain. So if we know that gay men perform differently in these kinds of tests, that suggests that part of the brain either is structurally different or functions in a different way. That gives us an insight into brain development.
"Thanks to MRI scans, we also have the technology to look at the brain directly rather than just carry out problem solving tests on people. The studies in the last two years strongly suggest that in the adult gay brain, and lesbian brain, it is wired very differently to the straight brain.
In 2008, Swedish scientists at the Karolinska Institute compared the brain hemispheres of healthy gays and lesbians with heterosexual male and female adults. Read their findings, here.
In Gay by nature: Part two, Dr. Rahman addresses the issue of gay stereotypes and refutes psychoanalytic theories of why some people are gay. Dr. Rahman also suggests that research into gay brains may help combat homophobia. To read Part two, click here.
Read Gay by nature: Part one in its entirety.
Related stories can be found on NowPublic Human Sexuality Special News Coverage.