Saturday, 21 March 2009

A Summary of the State of the Art

Here's a reply I wrote to a member of OII - Organisation Intersex International - who asked just exactly what the HBS - Harry Benjamin Syndrome -political group was, in Australia.

It details my thoughts as they've crystalised on the etyology of Transsexuality, what it is, what causes it, and is a decent summary of what we know so far.

I can't give you "the" picture of HBS. I have some significant differences from may others on the issue.

For example, I believe that the gender binary is merely a very good approximation. Just like it's best to treat the Earth as being flat, locally. It's not, but it works best when walking to the corner shop if you treat the journey as if it is.

I believe that gender is in the brain, and so is sex, and sexual orientation. But again, though it's really useful to make categories of "male", "female", "straight", "bi" etc, and while those definitions may be exact, not just approximate, descriptions of most people, for a large proportion they are only approximations, and for a small minority, bad approximations at that. So bad they're not just useless, but counter-productive.

I believe that it's most likely that "typically female" or "typically male" patterns of neural development, stereotypes to which individuals conform to a large degree (usually) happen as the result of the foetal hormonal environment, as modified by genetics. Atypical development may happen, and we're talking only about the lymbic nucleus here, the brainstem, hypothalamus etc , areas whose development is mostly or completely set before birth.

These lymbic patterns affect later development of the cerebral cortex (in ways we don't understand - insert much handwaving here, though not elsewhere), in particular lateralisation and connections in the corpus callosum. In addition, the typically female or typically male instincts and emotional responses dictated by the pre-natally hard-wired lymbic system later on lead to the child comparing themselves with peers and adults, and consequently developing a male or female "gender identity" based on who they most resemble.

Just to complicate things... the brain is such a complex organ, that in this case it's useful to see it as an assembly of different organs, much as the reproductive system isn't a single organ, but an assembly, where different parts can conform to different degrees to either of the standard stereotypes. And just as the reproductive system changes morphology, and is to some degree "plastic" and subject to environmentally caused change (notably at puberty), so are the higher brain structures. Yet no new structures develop, the basic pattern is set before birth.

So an individual, whether cissexual, transsexual, or intersexed, will usually have a brain that conforms strongly to a masculine stereotype in some areas, and weakly to a female stereotype in others, or the reverse. The areas will differ between individuals though, and what evidence we have from cases of 5ARD and 17BHDD is that perhaps a third of people can function in either gender role. I wish we had more to confirm this. For that matter, I wish we understood what gives rise to left-handedness or ambidexterity, areas of brain development post-birth that are equally as radical (neurologically speaking) as many of the bimodal sex differences.

In practical terms, one of the most important areas is that of body image. Most will have a strong body image conforming to one stereotype or another, but some will not. This is observable in Intersexed people, many of whom "want to be normal", but some of whom object strongly to the concept of having their genitals surgically altered, even though they may be atypical. In the worst case, an Intersexed person who "wants to be normal" has had their genitals surgically changed to make them as abnormal as they can be, to be those of the opposite sex to the stereotype given by their "body image".

Where I radically differ from the standard HBS model is that the evidence to me shows that while there is a strong correlation between stereotypes-conformity in all parts of the brain, it's not exact. As just one example, it's not just possible, it's inevitable that there will be some people with strong male identities, whose brains in general conform to a typically male stereotype, but whose body image is that of a female to a greater or lesser degree. Some men feel most comfortable having feminised genitalia, and some women feel most comfortable having masculinised genitalia. And many more are just afraid of surgery, and want to live with whatever they're lumbered with, even if it's not optimal. All-consuming desire for typical genitalia is *not* a reliable touchstone for determining gender, any more than chromosomes are a reliable touchstone for determining sex. They're just really, really good approximations.

The standard HBS model, as I interpret it, as over-simplistic. There are male brains, and female brains, period. If you have a male brain, you *NEED* (not just desire) male genitalia, and if you have a female brain, you *NEED* (not just desire) female genitalia, and that's all there is to it. Everything else is "psychological" and any ambiguity or anomaly a "mental illness". I don't agree with this, as it results in trying to coerce observations into fitting what is almost a religious theory rather than a scientific one. It's basically correct, but only as correct as saying the Earth is flat. The further you go from the local area, the less useful such a view becomes. Go far enough away, and it breaks down completely.

One more thing, which may colour my interpretations of the data. This is the Australian HBS group, and in Australia, it is the medical and legal position that what is termed "transsexuality" is a form of neurological intersex, where (parts or a part of) the brain is cross-gendered compared to the majority of the rest of the body.

7 comments:

sumptos devil s advocate said...

But what parts of the brain are most important for this?

"As just one example, it's not just possible, it's inevitable that there will be some people with strong male identities, whose brains in general conform to a typically male stereotype, but whose body image is that of a female to a greater or lesser degree. Some men feel most comfortable having feminised genitalia, and some women feel most comfortable having masculinised genitalia."

What are these identities and body images?

SA-ET said...

For example, I believe that the gender binary is merely a very good approximation.

Perhaps, if one were to intellectualize the issue enough, I could agree. However, from a practical standpoint I don't feel it's accurate to throw the gender binary into question because their is an extremely small percentage of people who don't fit exactly into it due to some biological/genetic miss. Because some people may be born without all four limbs does not challenge, nor make it an approximation, the premise that homo sapiens are born with two arms and two legs.

Zoe Brain said...

SDA - we don't know.

In order to determine what parts of the human brain are involved with what functions, we have to use animal experiments of dubious morality, and just as dubious applicability, or rely on "Nature's Experiments'. That is, people whose brains have been significantly damaged in very precise areas.

See for example Oliver Sachs' work The Man who mistook his wife for a Hat.

It's worse dealing with the lymbic nucleus, as too much damage in the nearby area leads to loss of ability to breathe, etc. So we don't have nearly as much data as we do for other, higher brain functions. What we do have is from damage to the connections between this part of the brain and the rest, which has enabled us to make deductions about which bits must do what.

There is much work to be done here.

Zoe Brain said...

SA-ET - perhaps my views are coloured by the fact that my father-in-law only had one arm.

H.Sap is bipedal, and has 2 arms and 2 legs.

But individual humans may have fewer or (very rarely) more.

It's a semantic issue, but the view that "humans in general have 2 arms and 2 legs, but that's only an approximation" is supported by the various legislation we have regarding disabilities, and even the Special Olympics. That "humans are born with 2 arms and 2 legs" is a better approximation, as most who don't conform to the norm lose them after birth.

For that matter, defining "what is an arm" can be difficult - does someone who has polydactyly, more than the usual number of fingers, have an arm? I think so, even though they don't conform to the norm. What about children born with phocomelia, as sometimes just happens, or as notoriously caused by Thalidomide? At what point does a limb conform to the norm so much that we can call it an arm or a leg?

Yet no-one denies the reality that there are arms and legs, that the definition is not a mere social construct, not arbitrary.

I was diagnosed as a mildly IS male in 1985. And re-diagnosed as a severely IS woman in 2005. From a legal standpoint, in the UK I'm male (though somatically female according to my UK passport), and in Australia, female. While I identify as a woman, not a Transsexual, or a Transgender, or a Transwoman, or an IS-woman, or a gender-bender,and certainly not "Queer", but someone who fits really neatly into the standard gender binary, I have to admit that for me, the categories "male" and "female" are only approximations, somatically speaking, as I've been diagnosed as both. I don't like that or want that, but what I want or like is irrelevant.

An analogy - blindness. While everyone agrees there are distinct concepts of "blindness" and "sighted", the same person with very limited vision can be "legally blind" in one jurisdiction, and not "legally blind" in another. I'd thus say that sighted/blind is an approximation, not a concrete binary.

I think we agree on the thing itself, but disagree on the wording used to describe it - a semantic disagreement only.

sumptos devil s advocate said...

Zoe Brain,

But what is this identity and what is this body image?

Zoe Brain said...

Good questions!

I can answer the second one easily enough: the instinctual knowledge of how many arms, legs, eyes etc you're supposed to have, and the shape of your genitalia and secondary sex characteristics.

Rarely, people with some kinds of lesions in particular parts of the lymbic system become "detached" from parts of their bodies, typically limbs. They feel as if you'd feel if someone grafted a pair of tentacles on your shoulders, as if these appendages just didn't belong.

There's some flexibility there, and people with extra fingers and toes generally don't feel uncomfortable with that. But people who have lost limbs due to amputation often suffer severe psychic trauma, above and beyond what is reasonable to have due to disability. Their bodies feel the wrong shape now, it doesn't match their body image.

People with paralysed as opposed to amputated limbs still get the trauma from the disability, but don't get the much more severe trauma from violation of the body image.

But it varies, and some people don't get much psychic trauma at all. We don't know why.

As regards gender identity, see Milton Diamond's works on the subject. There's a URL in my (notorious? infamous?) "Bigender and the Brain" post.

sumptos devil s advocate said...

What is the difference between projecting onto others (in, say, a narcissistic way) and identifying with others?