Understanding Gender Dysphoria, page 8
Can any one theory really speak to the complex and diverse presentations in our culture today? No.
Most of the research on causation has focused on the experiences of transsexual persons. Recall that these are persons whose cross-gender identification is profound. They typically identify as the other gender and may decide at some point to pursue hormonal treatment and/or sex-reassignment surgery.
Many of the debates about causation have been between those who argue for a significant biological component that reflects more essentialist assumptions and those who rely more on a clinical typology based on sexual orientation. There are also those who describe a different kind of biological contribution in temperament/personality that interacts with the environment in a way that contrasts with the views of these others.
As we turn our attention to the different theories of etiology, it should be noted that these debates also occur in the sociocultural context of what has been referred to as identity politics.12 As has been well documented, much of the ground that has been gained in discussions centering on homosexuality has been due to an essentialist view of sexual orientation as something immutable and essential to who someone is (their identity) as a person.13
Nowhere have conceptual struggles over identity been more pronounced than in the lesbian and gay liberation movement. The notion that sexual object choice can define who a person is has been profoundly challenged by the advent of queer politics. Visible early lesbian and gay activists emphasized the immutable and essential natures of their sexual identities. For some, they were a distinctively different natural kind of person, with the same rights as heterosexuals (another natural kind) to find fulfillment in marriage, property ownership, and so on. This strand of gay organizing (perhaps associated more closely with white, middle-class gay men, at least until the radicalizing effects of the AIDS pandemic) with its complex simultaneous appeals to difference and to sameness has a genealogy going back to pre-Stonewall homophilic activism.14
Discussions centering on people who experience gender dysphoria are also moving in a similar direction in which the paradigm is one of essentialism that distinguishes types of persons: transgender rather than cisgender. Some people will use transgender to describe how they are (“I am a person who is transgender, by which I mean I am a person who experiences gender dysphoria”) while others will use transgender to describe who they are (“I am transgender, a member of the transgender community”).
The biological essentialism that has been associated with sexual orientation (with an emphasis on neurobiological brain differences, markers on the X chromosome, twin studies, etc.) is being discussed with reference to a corresponding essentialism associated with gender identity, particularly as it is conceptualized in the brain-sex theory, which I will discuss below.
A proper critique, however, cannot be based on how people may wish to use research in the context of a larger strategy (of, say, liberation or civil rights or identity politics) but must be understood on its own terms. What do we know about causation from the research that has been conducted so far?
This critique cuts both ways: social conservatives can also have a knee-jerk reaction to research that they believe is being used by those who are advancing a social agenda of one kind or another. Put differently, if Person A is concerned that Person B is citing research to advance the deconstruction of sex and gender norms, Person A could be equally guilty of not looking at the research, simply rejecting any and all research put forth by Person B on the grounds that Person A is against the agenda put forth by Person B.
So we face the challenge of sorting through the research findings in the context of a larger cultural war about the use of such research in policy development and various legal battles.
I will share some information on the most widely cited theories and studies while moving us toward a more integrated model.
Brain-Sex Theory
The most popular theory among those who believe nature is making the significant contribution to gender dysphoria is called the brain-sex theory. It is a theory that is tied, or potentially tied, to a number of hypotheses that I will summarize below. The idea is that there are areas of the brain that are different between males and females. Researchers refer to these areas of the brain as sexually dimorphic structures. “Brain sex” refers to ways in which the brain scripts toward male or female dispositions or behaviors. Diamond explains it this way:
Since the brain is the organ determining or scripting male or female behaviors, the term brain sex is short hand to reflect on how an individual thinks and organizes the world; whether in stereotypical male or female ways. It is certainly true that the brain is the most used sexual organ of the body and the term brain sex reflects its male or female disposition. It directs the individual to think and act more like a stereotypic male or more like a female.15
The background to the brain-sex theory is that scientists have established that “the presence of testosterone in utero leads to the development of external male genitalia and to a male differentiated brain.”16 But these are two distinct processes; they do not occur at the same point in fetal development. In other words, sex differentiation of the genitals and sex differentiation of the brain take place at different stages of fetal development. Proponents of the brain-sex theory identify this discrepancy as significant for gender incongruence: “As sexual differentiation of the genitals takes place much earlier in the development (i.e., in the first two months of pregnancy) than sexual differentiation of the brain, which starts in the second half of pregnancy and becomes over upon reaching adulthood, these two processes may be influenced independently of each other.”17 Is it possible, then, that “a discrepancy may exist between prenatal genital differentiation and brain differentiation such that the external genitals develop, for example, as male while the brain develops as female”?18
Researchers, then, look at prenatal hormonal exposure as a possible key to the etiology of gender dysphoria.
Prenatal hormonal hypothesis. Left-handedness is associated with prenatal hormonal exposure and has been a part of the discussion about etiology. The idea here is that perhaps gender identity differences are the result of differences in exposure to prenatal hormones at critical months in utero. Empirical evidence in support of this hypothesis includes findings suggesting a greater likelihood of left-handedness among transsexuals,19 although, obviously, the vast majority of left-handed individuals are not gender dysphoric. The point is that when gender dysphoria is present, that person is more likely to also be left-handed than right-handed.
Similarly, studies of finger length ratio have suggested a difference that some scientists believe speaks to etiology. Finger length ratio is believed by some scientists to be another marker of prenatal hormonal exposure. Those who support this view cite evidence suggesting that the ratio of the index finger and the ring finger is affected by exposure to testosterone in utero. The lower this finger length ratio the greater the exposure to testosterone. There is an on-average difference in that ratio between the sexes, with males having a lower ratio than females (i.e., this finger length ratio is sexually dimorphic). Some studies20 have provided evidence that the finger ratio of transsexual men is in the range of biological females and not in the range of biological males who are not transsexual.
Although these studies are interesting, there is research that does not appear to support the theory. For example, consider a biological/genetic female who has been diagnosed with congenital adrenal hyperplasia (CAH), a genetic condition that affects her adrenal glands’ production of cortisol and hormones such as aldosterone and testosterone. Her body produces too much testosterone, which leads to her being born with ambiguous genitalia (typically an enlarged clitoris) despite having normal (for a biological female) internal reproductive structures. The point is: it is uncommon for females diagnosed with CAH to develop gender dysphoria.21
Neuroanatomic brain differences hypothesis. A related line of research has been in the area of neuroanatomic brain differences. This hypothesis looks at brain morphology or structure. Research has already documented differences in neuroanatomical regions of the brain between males and females. Researchers have then conducted studies to see whether areas of the brains of male-to-female transsexuals are more in the male or female range.
One area of the hypothalamus in particular has received quite a significant amount of attention. Studies of the central subdivision of the bed nucleus of the stria terminalis (BSTc), an area of the hypothalamus, has been in the female range in terms of volume of cells22 and number of cells23 among male-to-female transsexuals.
As we move into a discussion of this research, we should recognize that these are again typically small studies that include samples of transsexuals, most of whom have undergone hormonal treatment or have been engaging in a cross-gender role for years. But this research has been taken by proponents of the brain-sex theory as empirical support for nature rather than nurture in the etiology of gender incongruence.
Probably the most frequently cited study in this area is the study by Jiang-Ning Zhou and colleagues,24 in which the researchers compared an area of the brain of six MtF transsexuals to the same brain region in typical/cisgender males and typical/cisgender females. They reported that this region of the brain (the BSTc) was larger in cisgender males than in cisgender females (44% larger), and that this same region of the brain of MtF transsexuals was actually within the smaller, typical female range than the male range. Despite the small number of MtF transsexuals and the fact that they had all been using feminizing hormone therapy, this study made a significant and lasting impact on how many would later argue from an essentialist position about the biological basis for transsexuality.
The next most frequently cited study in this area is the one conducted by Kruijver et al.25 Whereas the Zhou et al. study examined the size of the BSTc, the Kruijver et al. study examined the number of cells in the BSTc area among seven MtF transsexuals and found that the neuron count was in the range of the thirteen typical/cisgender females. Again, this has been widely viewed by proponents as offering empirical support for the brain-sex theory in which the brains of transsexuals are thought to have a sex-reversed structure.
The size of and number of cells in the BSTc had been shown to be related to gender dysphoria in the Zhou et al. study26 because it was in the female range among males who identified as transsexual females. A question that arose was this: if there is evidence of a sex-reversed structure, when does this sex differentiation actually occur?
Wilson Chung and his colleagues27 conducted a study that looked at when the BSTc actually becomes sexually dimorphic. The researchers confirmed that the BSTc was larger (as the Zhou et al. study showed) and contained more cells (as the Kruijver et al. study showed) among men than women. Those differences, however, were noted not in childhood but in adulthood, which went against some of the commonly held assumptions at that time. The researchers were surprised by these findings: “The sex difference in BSTc volume, which reached significance only in adulthood, developed much later than we expected. . . . Therefore, marked morphological changes in the human brain, including sexual differentiation, may not be limited to childhood but may extend into adulthood.”28
The problem with these results, say critics,29 is that most people who experience gender dysphoria recall concerns in their childhood: “Epidemiological studies show that the awareness of gender problems is generally present much earlier. Indeed, ~67–78% of transsexuals in adulthood report having strong feelings of being born in the wrong body from childhood onward, . . . supporting the idea that disturbances in fetal or neonatal gonadal steroid levels underlie the development of transsexuality.”30
The researchers themselves do not see their findings as ruling out “early gonadal steroid effects on BSTC functions”; rather, they point to animal studies in which the earliest effects could be on “synaptic density, neuronal activity, or neurochemical content” that affect gender identity but are not measurable in terms of the volume and number of neurons until adulthood.
So critics of the brain-sex theory see the study as undermining the theory, while proponents of the brain-sex theory assert that the differentiation begins at an earlier stage but that what can be measured (by volume/number of neurons) will only be measurable later. Both camps (opponents and proponents of the brain-sex theory) incorporated the study into their overall view of causation.
Supporters of the brain-sex theory conclude that transsexualism is a “neuro-developmental condition of the brain,”31 or, as Diamond puts it: transsexuality is “a form of brain intersex,” citing many of the studies noted above.32 Of those who adhere to the brain-sex theory, one variation presented by Diamond is referred to as the biased-interaction theory of psychosexual development. Here is the background to that theory:
In general, biological factors starting from XY chromosomes produce males that develop into boys and then men with whatever characteristics are appropriately seen as masculine for society and females develop into girls and then women with whatever characteristics are appropriately seen as feminine for the same society. Differences from the usual course of development are not seen as “things gone wrong” or errors of development but as to-be-expected occasional variations due to chance interactions of all the variables involved.33
The background a person has is reflected in what Diamond refers to as “organizing factors” such as “genetic and hormonal influences laid down prenatally that influence adult behaviors once set in motion by pubertal or post pubertal activation processes or events.”34 These organizing factors predispose or influence or “bias subsequent responses of the individual; they predispose the person to manifest behaviors and attitudes that have come to be recognized as predominantly masculine or feminine.”35
Diamond offers an extended discussion about the process and how it might relate to a person who experiences a gender identity conflict:
Starting very early in life the developing child, consciously or not, begins to compare himself or herself with others; peers and adults seen, met, or heard of. All children have this in common. . . . In so doing they analyze inner feelings and behavior preferences in comparison with those of their peers and adults. In this analysis they crucially consider “Who am I like and who am I unlike?” Role models are of particularly strong influence but there is no way to predict if a model will be chosen, who will be chosen, nor on what basis chosen. In this comparison there is no internal template of male or female into which the child attempts to fit. Instead they see if they are same or different in comparisons with peers, important persons, groups or categories of others. . . . It is the “goodness of fit” that is crucial. The typical boy, even if he is effeminate, sees himself as fitting the category “boy” and “male” and eventually growing to be a man with all the accoutrements of masculinity that go with it. Similarly the typical girl, even if quite masculine, grows to aspire being a woman and probably being a mother. The comparisons allow for great flexibility in cultural variation in regard to gendered behaviors. It is the adaptive value of this inherent nature of brain development that trumps a concept of a male-female brain template to organize gender development.
In most cases the contributions from nature that lay out a kind of “brain template”36 correspond with a person’s primary and secondary sex characteristics, their genitals/anatomy, and the sociocultural context in which that child is reared. In those rare instances in which these dimensions are not in alignment, we witness an experience of gender identity conflict that can range from mild to quite severe.
The average male fits in without difficulty, the atypical one who will exhibit signs of gender identity dysphoria, for instance, does not see himself as same or similar to others of his gender. He sees himself as different in likes and dislikes, preferences and attitudes but basically in terms of identity. There will be a period of confusion during which the child thinks something like Mommy and Daddy call me boy, and yet I am not at all like any of the others that I know who are called “boy.” While the only other category the child knows is girl, he develops the thought that he might be or should be one of those. Initially that thought is too great a concept leap to be easily accepted and the child struggles in an attempt to reconcile these awkward feelings. The boy might actually imagine he is, if not really a boy than possibly an it, an alien of some sort or a freak of nature. Eventually he might come to believe, since he knows of no other options, that he is a girl or should be one. And with a child’s way of believing in Santa Claus or the Tooth Fairy he can come to expect he will grow up to be a woman. With experience and the realization that this won’t happen of its own accord the maturing child may begin to seek ways to effect the desired change. A female can experience an opposite scenario.37
What is attractive about the brain-sex theory and various theories associated with it is that it attempts to offer a unifying theory of gender identity concerns in a way that is supported (according to proponents) by research.
Limitations. Several limitations of this research should be noted. These limitations include (1) small sample sizes, (2) post-mortem samples in which transsexual persons frequently used hormone therapy, and (3) emphasis on morphology rather than a range of other considerations.
In terms of sample sizes, the fact that gender incongruence and transsexality are so rare makes it exceedingly difficult to obtain a large sample to conduct research. The most influential studies38 in this area reported on findings of the neuroanatomical brain regions of six male-to-female transsexuals39 and seven male-to-female transsexuals.40
