Section 2: The science to date

At a scientific level, our understanding of the nature of homosexuality has come a long way in the last 30 years or so. However, much of the recently gained knowledge have been seen as threatening to established religious and cultural ideas, and there has been, as a result, a lot of resistance to them. Moreover, many recent discoveries have been tentative, pending replication, and paint a picture of sexuality that is hugely complex and nuanced. Without a simple soundbite quality to it, it has not fired the popular imagination. Hence, millions of people are not familiar with our more recent understanding of homosexuality, and if they think of the subject at all, continue to regurgitate obsolete theories which serious researchers have long ago abandoned.

The obsolete theories that don't threaten heterosexual norms

These obsolete theories came from a time when we really knew nothing at all about homosexuality. We didn't even know there were homosexually-oriented persons other than the most egregious flamboyant cross-dressing males. They were the visible tip of the iceberg, so to speak, and their monopoly of representation of non-normative sexuality led many people to think that homosexuality equated with swishy males.

In such circumstances it was easy to imagine that homosexuality was the result of absent male role models or over-dominant mothers, or both. Many people continue to rehash this explanation today.

Another popular explanation is by way of trauma. Either the person was raped and molested when young by an adult of the same sex, and thereby turned homosexual (although how that can make a person homosexual is never detailed), or the person has had a traumatic relationship with a person of the opposite sex, retreating thereafter to the affection of the same sex instead.

The appeal of these theories is that they are simple, and they do not undermine the assumption that human sexual attraction is universally in the direction of the opposite sex. Only when there has been trauma or severe developmental lacuna, does a person turn out emotionally handicapped, as a homosexual person is automatically assumed to be.

Homosexuality as disease

From here, it's a short hop to seeing homosexuality as a psychiatric abnormality, and it did not help that psychologists and psychiatrists in Europe and America were the first ones to study sexuality. Before long, homosexuality was firmly planted in the realm of psychiatric illnesses. Classified as a medical condition, all manner of attempts were made to cure people of it. People have had parts of their brains excised or cauterized. Others have had electric shock treatments or chemical castration. Today, such "treatments" would be considered crimes against humanity.

Yet, after decades of this, there was not a single case of a successful "cure". Social and psychological profiling of homosexual populations also failed to substantiate in any consistent way, the old theories of absent fathers, dominant mothers, physical or emotional trauma. If anything, the more the researchers looked, the more they found how well-adjusted the vast majority of homosexual persons were, excepting the need to be in the closet.

With neither theoretical support from research, nor practical success from what were instead beginning to be seen as unconscionable abuses, homosexuality was removed from the American Psychiatric Association's list of mental illnesses in 1973. The World Health Organisation did likewise in 1993, Japan in 1995, even China in 2001.

Biology

In contrast to the complete failure of social and psychological research to explain homosexuality, there has been intriguing progress in the fields of neurobiology and genetics. The various findings are excellently summarized in a groundbreaking article by Chandler Burr in the Atlantic Monthly. See the archived version at http://www.theatlantic.com/issues/97jun/burr2.htm

Although that article was published in 1993, the general direction of research outlined there remains valid today. Burr expanded the issues he covered in that article into a book, A Separate Creation (Hyperion Press) in 1997.

It's always a problem communicating scientific progress to non-scientific readers. People tend to expect simple, definitive answers NOW, when that is not the nature of science. Scientific knowledge grows by accretion. Empirical observations are collected, theories are tested against them. Along the way, some theories get substantiated, while others are shown to be at variance with factual observations, and usually discarded. Through this process, some explanations gradually become more and more convincing, but there is seldom at any time, a clearcut, simple-to-grasp, made-for-TV explanation.

A good example of the confusion that can occur when laymen with political agenda misunderstand science can be seen in this excerpt from Chandler Burr's book, A Separate Creation.

Coming back to the science, at this point, two areas of research look promising: genetic causation and the influence of prenatal hormones.

Twin studies and genetic correlation

As described in Chandler Burr's article, there was a landmark study by Bailey and Pillard which showed a strong correlation between homosexual orientation and genetic closeness between siblings. If one identical twin was homosexual, there was a 52% chance that the other would also be homosexual. Identical twins, as most readers will know, share the same genetic make-up. The concordance rate for fraternal twins was much lower, at only 22%. With adoptive brothers, who do not share any genetic inheritance, the concordance rate was only 11%.

Even as researchers have yet to identify which parts of the human genome code for sexual orientation, and how those genes work, these findings by themselves are so compelling, it's quite impossible now to deny that genes do play a role. The researchers also found that the genetic influence followed the maternal line.

Yet, we can also say that genes are not the only factor at work, for otherwise the concordance rate between identical twins should have been 100%. There are clearly other factors involved.

Hormonal influences in utero

Of these, the next most likely case can be made for the influence of prenatal hormones. Evidence is accruing through various studies that our brains are not completely blank when it comes to sex and sexuality. There are discernable anatomical differences between the male and female brains. And our sense of whether we're male or female comes in part from some hard-wiring in our brains, not entirely because we're taught to think male or female. Likewise, there has been evidence from research by Dorner and others that our brains are pre-wired to be attracted to other males or females. It is believed that our sense of our own sex, and our object of attraction were formed by the influence of hormones on our developing foetal brains. It's too complex to get into the details here, but Burr's article gives a good summary up to 1993.

More recently, evidence has been accumulating, e.g. from Blanchard and others, that homosexual orientation in males varies with birth order. The more older brothers (but not sisters) a male person has, the higher the likelihood that he is homosexual. Why should this be so? It's too early for answers yet, but it seems likely that something about a pregnant woman's antibody interaction with foetal sons is interfering with the development of the foetal brain. The article "The big brother effect" in the 29 March 2003 issue of New Scientist goes into considerable detail about this latest avenue of research.

One thing to note: this effect is not noticeable in female homosexuals. Neither older sisters nor older brothers have an influence. The simplistic assumption that what we learn about the biological causation of male homosexuality will apply to female homosexuality clearly does not hold.

Compared to the steady accumulation of knowledge about possible biological causes, there is still no scientific support for theories (now looking more and more like myths) about socialisation and upbringing as causative factors. As psychologist Ray Blanchard from the Centre of Addiction and Mental Health in Toronto said (quoted in new Scientist, 29 March 2003), "The theory that early childhood experiences lead to homosexuality has had 100 years, and they've come up with zip."

Even in the observation that younger sons were more likely to be gay, where the kneejerk response might be that perhaps mothers treated younger sons differently, there is a parallel finding that indicated biological causes. It has been found that the ratio of the length of the 4th finger to the 2nd finger similarly varied with birth order. Since it is generally accepted that our physical traits are predominantly determined by our biology, it stands to reason that the trait of homosexuality that correlated with this physical characteristic of finger lengths had similar biological causes rather than be due to an unrelated cause - mothers' attention.

Probably multifactorial, but mainly multi-bio-factorial

In short, serious reseachers now overwhelmingly believe that homosexual orientation is not a matter of choice, and that biological factors predominate. However, there is almost certainly no single cause, but a number of different factors. In some homosexual persons, some factors may have been more important than others. And it looks likely that there are different factors for male and female homosexuality.

Science doesn't really answer moral and political questions

So what does science tell us about how to treat homosexual persons in our midst? Virtually nothing. These are social, ethical, political, even moral questions which have to be resolved within their own domains. Science can however point out fallacies in certain arguments used by one side or another in the debate.

The most obvious one is that homosexuality is behaviour that some people choose to engage in, and therefore society can justifiably apply sanctions to force them to unchoose. To the extent that homosexual orientation is now believed to be predetermined by biology -- and there has been no example of anyone successfully changing his orientation (as opposed to hiding or suppressing it) -- this position is strongly contradicted. However, orientation is one thing, engaging in homosexual sex is another, and if the injunction is to desist, but not necessarily to unchoose one's orientation, then science has nothing to say about it.

Homosexuality occurs in nature

Another position contradicted by recent research is that homosexuality is "unnatural". If "unnatural" is taken to mean that something does not occur in nature, then the many observations of animals, including chimpanzees, our closest cousins, engaging in same-sex behaviour would not at all support this argument.

But often, when someone uses the "unnatural" argument, he doesn't mean it in that sense. The word is used to mean that it does not fit the purpose of sex, which many people strongly believe to be procreation. At this point, we take leave of science, because science doesn't tell us what the purpose of sex is, anymore than it tells us what the purpose of eating chocolate, or watching the sunset is, however much we enjoy both. Purpose is something that humans impute to an activity, and the answer may well vary from culture to culture.

Section 3 will tiptoe into these thorny issues.

Section 1: Orientation or lifestyle?
Section 2: The science to date
Section 3: Norms, censorship and history
Section 4: Homophobia