| Birds, Bees, And Neurobiology: Sexing The Brain |
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| Opinion - Global Warning | |||
| Written by Lisa Jain Thompson | |||
| Tuesday, 24 June 2008 17:00 | |||
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Springfield, VA, USA. Early in fetal development, before even a glimmer of genitalia, the central nervous system acquires its basic structure.
It is here, deep within the most complex structure in the embryo that Harry Benjamin Syndrome (HBS fna transsexuality) begins.
Ongoing scientific research strongly suggests that HBS is a birth condition that misaligns innate neurobiological makeup and external genitalia: a person who is neurobiologically female exhibits male sexual anatomy; a person who is neurobiologically male exhibits female externals.
Neural development generates the most complex structure within the embryo, beginning as a simple neural plate region of the ectoderm before unfolding to form a groove and then a neural tube. This is the basis for differentiation into spinal cord and brain.
The process is not quick: neural development begins early and completes late in the gestational cycle, part of which takes place outside the mother’s body. The lengthy development period provides a long in utero opportunity for neurobiological insult (injury or trauma) to the fetus that has consequences to proper development of the nervous system. Major classes of neural abnormalities (neural tube defects) point to structural abnormalities that can result in retardation and number of other conditions of impaired functioning such as autism.
Of greater significance to those born with HBS are disruptions to the encoding sequences necessary for the development of genitalia. Brain and body development processes are not conditional, but proceed in parallel using shared resources.
The configuration of a brain does not trigger matching genitalia. The physical configuration of a penis or a vagina does not result in a matching brain. Both development cycles are triggered much earlier, following conception and before the appearance of a neural crest.
The underlying "cause" of HBS is yet to be determined, but clues have and are emerging from studies of blastocyte differentiation, iMRNA, neuronal communication, and others. If verified by further research, the studies would represent a physical observation of the signs and characteristics of HBS but not necessarily an indication of cause.
The best that such studies reveal are the properties of the brain that typifies HBS existence without necessarily revealing a material cause. A parallel observation would be that the documented differences between male and female brains are the material cause of their maleness and femaleness.
The studies seem to confirm, however, that in an ordered physiological system there is a match between a female brain and female genitalia. Certain other individuals (e.g., HBS women) exhibit neurobiological disorder: there is a mismatch between their female brains and anomalous genitalia.
The bottom line appears clear: not only are there physical differences between male brains and female brains, the brains of HBS women are configured female, most probably as a result of physiological processes that occur very early in fetal development. Additional research is expected to confirm this within a decade.
All of this brings us to the article that trigger this column and continues to send shock waves through gender theorists, the transgender community, and others who believe that the human condition is malleable and nurture will always override nature:
From the reaction, you would think someone had set off a dirty bomb in the middle of the university.
At this point, it should be noted that, although many social science personal observation studies assert a relationship between Harry Benjamin Syndrome and sexual orientation, such studies, by their nature, ignore the underlying neurobiological mechanisms that lie beneath the observed behavior and any such subsequent conclusions are unsupported by the available data. No scientific data or research exists that supports such a connection or conclusion.
The sexual orientation of HBS men and women follows the normal distribution curve of the general population with the majority of HBS identifying as heterosexual and a small percentage as gay or lesbian. The isolation of causative factors for sexual orientation could eliminate unwarranted associations and support more focused attention to the HBS condition.
Scans reveal that the brains of both homosexual men and heterosexual women are symmetrical — the right and left hemisphere are more or less the same size. Moreover, the brains of heterosexual men and homosexual women are asymmetrical — the right hemisphere is larger than the left. Further, scientists at the Stockholm Brain Institute have identified brain circuits that are link to emotional responses that are identical in gay men and straight women.
This research, like the research being done on the brains of HBS women and men, strongly suggests that biological factors — neurobiology to be precise — influence, if not cause, sexual orientation. Additional research needs to be done to determine if these biological factors develop in early neural development (like HBS) or from later influences in the womb (such as exposure to estrogen or testosterone).
In general, research repeatedly confirms that there are identified differences in spatial and verbal abilities that are link to both physical sex and sexual orientation. Study has revealed that straight women and gay men are better at certain language skills; conversely, lesbian women and straight men are usually better at spatial awareness. Current research has not yet confirmed that differences in brain shape are the cause of sexual orientation (or are a result of it), but studies have begun to investigate brain symmetry in newborns to see if there is a correlation with future sexual orientation.
A technique called positron emission tomography (PET) has examined the neuro wiring in the brains of a small group of volunteers. It appears that heterosexual women and homosexual men shared brain circuitry linking a region called the amygdala, which plays a key role in emotional responses, to other parts of the brain.
All of this research is part of a much larger effort to identify differences between the male and female brain with the goal of discovering why some mental disorders effect men and women differently (major depressive disorders are far more common and persistent in women, autism is four times more common in boys than girls). Scientists continue to study the brain to determine the underlying mechanisms that may cause the observed differences in distribution.
All of this — the ongoing hard science research, the consistent and repeatable findings, and the suggested long-term implications — raises alarms within both the social science community and the academic social theory experts. If there are truly physical causes for at least some of the differences between any two people, if many of the differences we see between people are born from physical causes and not as the result of social constructs, much of the social engineering advocated by university activists and other experts in the last century will be shown to be without foundation.
All the theses and journal papers that eschew hard science for nebulous social theory will be meaningless. The social scientists who now run from scientific theory and mathematics will be shown to be without clothes, talking heads more appropriate for an appearance on Oprah or Dr. Phil than for doing empirical research in neurobiology that is testable and reproducible by other researchers.
Physical differences between any two individuals do not mean they are unequal — just different. Everyone born in the United States is at liberty to pursue whatever life they wish — but different bodies have different tendencies.
I am at liberty to dunk a basketball into a ten foot (304.8 cm) high hoop. The physical structure of my five foot eight (172.7 cm) body precludes me from doing so without using a step ladder. It doesn’t mean that that I am less equal than Kobe Bryant, just different.
Differences in structure between male and female brains do not endow either with superiority — at worst, the differences complement each other. That the brains of HBS women fall within the normal female configuration should not come as a surprise — HBS is a medical condition that begins in the womb during the early stages of fetal development. That the brains of homosexual men resemble the brains of heterosexual women more than they do the brains of straight men or that the brains of homosexual women resemble the brains of heterosexual men more than they do the brains of straight women is not earthshaking.
Much of human behavior finds its origins in the physical neurobiology of the brain. In many ways society influence who we ultimately become when we are grown (Christian, Islamic, agnostic, Republican, or Democratic), but that does not mean we can deny the biological reality of our existence. Despite our personal beliefs and our social preferences, we must go where the science leads us.
To do otherwise is folly, academic credentials to the contrary.
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| Last Updated on Tuesday, 24 June 2008 10:36 |






Ms. Lisa Jain Thompson
The TS-Si News Service is a collaboration of TS-Si staff, contributors, and corresponding institutions. Contents do not necessarily convey official positions of TS-Si, its partners, or affiliates