What is up with the BSTc hype?
In certain brain sex studies that have been completed, it has been found that the BSTc volume and neuron count of m2fs is about the same as it is for natal females. This was found to be true, regardless of sexual orientation, age of onset (transition), and regardless of exposure or lack of, to female hormones, in study subjects.
Likewise, the BSTc size and neuron volume of f2ms is about the same as it is for natal males.
What is the role of the BSTc in GID or transsexualism?
Currently, no one knows. This is important because, you cannot simply point to this study, and then claim “m2f transsexuals are neurologically women”. That is a huge ginormous conclusion-leap that is not substantiated by the current evidence.
What about the INAH3 hype?
Simply, INAH3 is another brain structure along with the BST that is located in the hypothalamus. Like the BST, the INAH is sexually dimorphic. This means that these structures are different sizes in males and females. While the BST does not become fully sexually dimorphic until early adulthood, the INAH differentiates between the ages of 2 to 4. Unlike the BSTc, the INAH3 is morphologically responsive to sex hormones. Meaning it will change size somewhat, due to male or female hormone exposure.
A recent study demonstrated findings much like the BST results. The physical size and neuron counts of the INAH3 in males was greater than in females. Transwomen had INAH3 values similar to women.
What is the role of the INAH3 in GID or transsexualism?
Unknown. We don’t have that information at present. This is important because, you cannot point to the INAH literature and say, “male-to-female transsexuals are neurologically female”. That is not what these findings indicate. They simply demonstrate that having a small limbic nucleus in certain areas is something that it seems m2fs share with natal females. That’s all it means.
What about the “Smell Study”?
One study was done in which a certain steroidal scent was offered to natal males and females as well as f2m and m2f transsexuals. The study showed that the brain area activated in natal females and m2fs was very similar. So you could say, male-to-female transsexuals process certain smells like born-females. Interesting findings, but that is all you can say about that study.
Sexual behavior and sexual dimorphism, what do they have to do with transsexual brain studies?
Sexual dimorphism is differences in size or features, in males and females. Some examples in nature are: Most male bears, seals, ducks, deer and the sperm whale are larger than the females. Most praying mantis, golden orb weaver, black widow spider and killer whale females are larger than the males.
Certain sections of the human brain, namely the center of the bed nucleus of the stria terminalis and the third interstitial nucleus of the anterior hypothalamus are larger in males and transmen, and comparatively smaller in females and transwomen. The BSTc is sexually dimorphic in early adulthood, while the INAH3 is sexually dimorphic in early childhood.
Changes in the size and activation of the BST in rats has demonstrated a relationship to male rat sexual behavior. For a variety of nerdy reasons, researchers have assumed that the human BST is also related to human sexual behavior.
Human sexual behavior is not playing dress-ups, or acting girly or manly. It’s not how you walk and talk and comport yourself, which would be gendered behavior, which is learned through socialization. Sexual behavior has to do with sex, actual copulation. It encompasses arousal behavior, courtship displays (flirting), and the act of sex itself.
In males, this is generally mounting behavior and ejaculation. In females, it is lordosis, and “receptive” posturing. It tends to be instinctive, as in, hardwired into your neurology. But there is an Italian study floating around out there, which demonstrated that castrated male rats given estrogen would go into lordosis when mounted by aroused and intact male rats.
What do these brain sexual dimorphism and atypical morphology findings really mean? What do they have to do with being trans?
The brain dissection studies and the Smell Study simply demonstrate that m2f transsexuals share some (as in, not all) brain morphology (structure and function) as natal-females. That’s all.
To use journalistic lingo, these studies are: “tantalizing”, “compelling” and “suggestive”. In terms of what these studies mean in relation to someone presenting with GID symptoms, or what having “female neurology” means for transsexualism, no one knows. And we are still a long way away from having fully established what female or male neurology encompasses.
That means you can drop the “Transwomen are female because they were born neurologically female, and since chromosomes and genitals can be confusing sometimes, neurology is really the only valid metric that counts for determining sex” nonsense, because that is not what these studies show. Got that transjactivists?
It is more accurate (at present) to say, “Transwomen have some shared neurological morphology with natal-females.” That’s it.
With that said, these findings help to understand, or at least shed some light on, why the trans tropes “born in the wrong body” or “always knew I was female” or “trans is a birth defect” propagate. Transsexuals are differently wired compared to people who have always felt comfortable in their sex and gender, this much is certain. How much of that different wiring occurs before birth and how much of it is developmental remains to be fully understood.
So what about the brain-imaging study?
Interestingly, a relatively recent brain imaging study indicated that pre-transition or pre cross-sex hormone exposed brains of m2fs showed brain volumes that are largely the same as non trans male brains. The study showed that in as little as four months, male brains treated with estrogen began to take on brain volume characteristics of natal-females.
What can we conclude from that brain-imaging study?
Simply, estrogen treatment feminizes the male-bodied brain, and taken from my own personal experience, these brain changes absolutely helps transwomen to think and feel more “female”.
These studies have some design flaws that need to be overcome, such as small number of brains dissected, and in some cases, lack of proper control groups for comparisons.
Also, a study that is “suggestive” or “compelling” is not the same as “conclusive” or “well-established fact”. Therefore, these studies need to be repeated and repeated again, with better controls and larger sample sizes, before any transwomen can run their mouth on the internets or IRL and claim, “transwomen are neurologically female”.
But even if it were true, so what? It takes more than a sexually dimorphic brain structure difference or two, to define “being female”. Proclaiming that these limited studies prove m2fs are “really born female”, is pure pomo bioreductionist transcentrist crap. It’s desperate fantasy.
It’s fantasy because, whether you want to admit it or not, your bodily sex sets a role for your childhood. If you have a penis, you will probably be socialized male, and you are never at risk of experiencing the unique issues of female biology, such as menses and vulnerability to unwanted impregnation.
It’s desperate because, without bioreductionist answers, you have nothing medical or biological to back you up when you try to explain to friends, family and employers (or insurers) what it means to be transsexual, which sucks.
My personal prediction is that with more studies, and similar research findings, the eventual conclusion will be: brain sex and neurology have an important role to play in biasing the transperson to what is currently being called “gender dysphoria”, and their desire to transition to the opposite sex.
How that opposite sex brain morphology asserts itself as dysphoric feelings of being in the “wrong body”, is anyone’s guess at this time. As it stands now, I think it is a fragile thing to hang your identity or validity on these measly transsexual brain sex findings.
Mostly the same PubMed articles that some transwomen spam on trans-critical feminist blogs and spaces. I did not bother to define BSTc or IANH3, (or things like the amygdala or the hypothalamus). Google helps.Regional gray matter variation in male-to-female transsexualism
http://www.ncbi.nlm.nih.gov/pubmed/19341803 Sex dimorphism of the brain in male-to-female transsexuals
http://www.ncbi.nlm.nih.gov/pubmed/21467211 A sex difference in the hypothalamic uncinate nucleus: relationship to gender identity
http://www.ncbi.nlm.nih.gov/pubmed/18980961 A sex difference in the human brain and its relation to transsexuality.
http://www.ncbi.nlm.nih.gov/pubmed/7477289 Male-to-Female Transsexuals Have Female Neuron Numbers in a Limbic Nucleus
http://jcem.endojournals.org/content/85/5/2034.full Male-to-female transsexuals show sex-atypical hypothalamus activation when smelling odorous steroids
http://www.ncbi.nlm.nih.gov/pubmed/18056697 Sexual Orientation: Toward Biological Understanding
http://www.questia.com/googleScholar.qst?docId=5001240134 Sexual differentiation of the human brain: Relation to gender identity, sexual orientation and neuropsychiatric disorders
http://www.sciencedirect.com/science/article/pii/S0091302211000252 The microstructure of white matter in male to female transsexuals before cross-sex hormonal treatment. A DTI study.
http://www.ncbi.nlm.nih.gov/pubmed/21195418 Bed nucleus of the stria terminalis: cytoarchitecture, immunohistochemistry, and projection to the parabrachial nucleus in the rat
http://www.ncbi.nlm.nih.gov/pubmed/2568370 Changing your sex changes your brain: influences of testosterone and estrogen on adult human brain structure-http://www.eje-online.org/content/155/suppl_1/S107.full