Rethinking Transgenderism

Rethinking the Conservative Approach to Transgenderism

by Jennifer Gruenke

within Bioethics, Science

July 29th, 2015

2223 128 2396

Conservatives do not take the introspective reports of transgendered people

seriously, but there are good scientific reasons for supposing that subjective

experience of gender is legitimate, even when it contradicts apparent

biological sex.

Transgendered people—people who appear to be one sex but report the

experience of being the other—have been in the news lately. The

conservative reaction to this phenomenon is, in some respects, puzzling.

Conservatives do not take these introspective reports seriously; they believe

that people seeking sex-change operations (now more often referred to as

sex-reassignment surgeries or gender-affirming surgeries) are almost

uniformly confused. Their approach to transgendered people is often polite,

even compassionate, but always firm in the conviction that transgendered

people are mistaken.

Now, subjective experience is often, but not always, reliable. In this case,

there are good scientific reasons for supposing that subjective experience of

gender can legitimately diverge from the sex of one’s reproductive organs,

so conservatives should be cautious in accusing transgendered people of

confusion. To show why this is true, I will show that developmental biology

demonstrates that there are multiple pathways of sexual development, that

one of those pathways is in the brain, and that the pathways of sexual

development can diverge from one another.

I will follow the convention of using the word “sex” to refer to the sexual

characteristics of the body exclusive of the brain, and “gender” to refer to

the subjective, internal experience of being a male or female. Sexual

characteristics are either primary or secondary. Primary sexual

characteristics develop prenatally and directly relate to reproduction (for

example, having testes vs. ovaries). Secondary sexual characteristics develop

at puberty, and may or may not relate to reproduction. For example, breast

tissue in females may eventually provide food for an infant, whereas facial

hair in males does not contribute to reproduction. The biological categories

of female vs male sexual characteristics are defined empirically. That is,

most babies with male primary sexual characteristics go on to develop a

particular set of secondary sexual characteristics.

Sex can be male, female, or in rare cases, somewhere in between, and can be

analyzed scientifically. As I will explain, gender appears to depend strongly,

but not exclusively, on the brain. Analysis of the brain can allow an outside

observer to make a reasonable, albeit imperfect, guess about a person’s


Mismatched Pathways of Sexual Development

Except in cases of monozygotic twinning, humans reproduce sexually. This

requires some individuals to be male and others female. The biological

triggers for an individual to be either male or female vary from species to

species. For most mammals, including humans, females usually have two X

chromosomes; males usually have an X and a Y chromosome. But for birds,

this situation is reversed, and for many species of reptile, sex is determined

by egg incubation temperature. Therefore differential sexual development in

the animal kingdom is not reducible to a common physical trigger.

Furthermore, some species, such as the clownfish, can change their sex over

the course of their lifespan. Thus it is a mistake to think of the sex of an

individual organism as fixed in every case for every species.

Humans, of course, are not fish, and we don’t observe our fellow humans

undergoing a natural change from one sex to the other. But individual

humans do go through a stage of development in which we have both male

and female physical parts at the same time. At about six or seven weeks of

development, a human embryo clearly has a human body. It has a head with

eyes and a torso with limbs. Fingers and toes are beginning to develop but

have not yet separated. Internal organs like the heart, brain, and liver are

present, if incompletely developed. Not surprisingly, given that these other

organs are well into their development, the reproductive organs are

developing, too. But instead of an incompletely developed version of either

male or female reproductive structures, the embryo has both. It has one set

of tubules that can develop into the uterus, fallopian tubes, and the upper

third of the vagina, and another that can develop into a series of tubules that

transport sperm. The gonads are also present, and can develop into either

ovaries or testes.

As the human embryo moves forward from this bipotential state, the default

developmental pathway is female. The Y chromosome normally initiates a

number of different pathways that inhibit the development of female

structures, instead masculinizing the gonads, genitals, and brain. It is

possible to have a mismatch between chromosomal sex and bodily sex. For

example, in cases of the intersex condition called complete androgen

insensitivity syndrome (CAIS), a human with XY chromosomes develops

into a girl due to the lack of androgen receptors; the androgens (testosterone

and others) that are present cannot affect their development. At puberty,

these girls develop physically as women and have a female gender identity.

They typically look even more feminine than XX women, who, at least, are

sensitive to the small amounts of testosterone that they have.

Their condition may not be discovered until they fail to menstruate as

teenagers. They have no uterus and have testes rather than ovaries. In this

case, the pathways of sexual development were mismatched. The male

pathway was activated for the gonads and the embryonic structures that give

rise to the uterus, but the female pathway was activated for the brain and

external genitalia.

Women with CAIS are easily diagnosed as intersex in early adulthood, but

more subtle types of intersex conditions might go unnoticed. In one case, the

XY karyotype of a fetus was determined during a check for chromosomal

abnormalities. But at birth the baby turned out to be a girl with normal uterus

and ovaries. It appears that in her case, all of the pathways of her sexual

development were female, due to a mutation that affects them all. If she had

not had her chromosomes tested, she might not ever have known that she is


Sexual Development of the Brain

So what do intersex conditions have to do with being transgender? One of

the pathways of prenatal sexual development is in the brain. There is good

evidence that babies are born with predispositions to consider themselves

male or female, that is, to have a gender. Some male infants who lose their

genitalia in accidents have been reconstructed as girls, with little success.

That is, they often grow up to experience the same thing that transgendered

people experience—their perception of their own gender does not match

their apparent sex.

Further evidence that infants are born with a predisposition towards a gender

is seen in cases of an intersex condition called 5-alpha reductase deficiency

(5-ARD). In 5-ARD, chromosomal males lack the hormone that

masculinizes the genitals, so they appear to be girls. But in most cases, the

child will identify as a male, despite being born with female genitals and, for

that reason, being raised as a girl. It appears that testosterone masculinizes

the brain, but not the genitals, during male embryological development.

Individuals with such a mutation end up with some parts of the body (testes,

brain) masculinized but others (genitals) following the default female


Other data support the conclusion that transgenderism has a genetic basis;

there is a strong concordance of occurrence among identical twins, but not

among fraternal twins. That is, if one identical twin is transgender, then, in

more than a third of cases, the other will be, too. Although we might expect

concordance to be higher, there is precedence for identical twins with

intersex conditions in which one twin is more severely affected than the

other. Because identical twins live in similar environments, we might think

that some of the concordance is due to shared environment. But fraternal

twins also share environment, and the study that found strong concordance

for identical twins found no concordance at all for fraternal twins. Human

neurology is complicated.

Thus gender appears to be influenced by genes but not absolutely

determined by them. Specific mutations leading to transgenderism have not

been discovered, but that is what we’d expect considering its rarity; one

report from Sweden, where transitioning from one sex to the other is

relatively well-accepted, shows that over 30 years (1972-2002), only 0.006%

of the population over age fifteen requested sex reassignment.

Possibly Reliable Introspection

If we put the pieces together, we know that there are multiple pathways of

sexual development and that they are not all regulated together. One

pathway is the development of the gonads into either ovaries or testes;

another is the development of external genitalia, and another is the

development of the brain to be predisposed toward one gender. We know

that the gonads and external genitals can differ from each other, and that

both can differ from chromosomal sex. So we ought to expect to find

individuals whose brain pathway differs from the other pathways. Given the

mutation rate, the size of the genome, and the number of humans in the

world, if a molecular pathway can be mutated without killing the individual,

the mutation will most likely show up in someone. And I would predict that

people with such a mutation would look just like cases of transgendered


Consider a case study of a genetic male with normal male genitalia who,

since childhood, has had the first-person perception of a female identity. It’s

possible that this is a case of confusion about identity rooted in

psychological trauma. But it’s also possible that this person has some

mutation that prevented the masculinization of the brain. The biology leads

us to expect that there will be some people in the latter category, even if we

don’t currently have a genetic test to identify these people. On the other

hand, psychologists do have some ability to identify trauma-induced identity

disorders, so in the meantime it’s possible to eliminate people from the

former category. We might first look for signs of dissociative disorders or

schizophrenia, for instance.

But unless such disorders seem to be the problem, isn’t it most likely that

this individual has some intersex condition, one in which the brain does not

match genetic sex, in a way that is—currently—only discernible through

introspection? Given how little is known about these rare cases, a high

degree of certainty is not possible, but inference to the best explanation

seems to warrant this conclusion.

To be sure, our subject would still be a genetic male with Y chromosomes in

the brain cells. But absolute reduction of sex to the sex chromosomes is not

supported by the biology, for as we have seen above, with the right mutation,

one could have a Y chromosome but an otherwise unambiguously female

body, including ovaries and uterus. For that reason, chromosomal

reductionism is an unacceptable account of sex.

An Objection

Now, it is worth considering a more principled objection from the

conservative front. Some might contend that, if we accept first-person

accounts with respect to gender identity, we will have no principled reason

to reject them in other cases. For instance, the first-person report is

unreliable in the case of anorexia.

An anorexic person is convinced that she is overweight, even when she is

already underweight. This, it might be claimed, is analogous to the case of a

transgender person. A transgender person might sincerely believe that he is

female, but that does not mean that he is not mistaken. Indeed, the objector

might press that brain chemistry cannot solve this problem. For suppose that

an anorexic person does have the brain chemistry of an overweight person,

and this similarity is accountable in terms of genetic factors; in such a case,

we would not say that the girl really is overweight, despite appearances.

We’d say that she is really underweight, personal conviction

notwithstanding. Anorexia just is a condition characterized in terms of a

desire to be thin in spite of already being thin; her brain chemistry and

emphatic beliefs don’t defeat this. Moreover, the anorexic person is not

correct merely because her reports match her brain and indeed her brain (if

not the rest of her body) developed along pathways characteristic of

overweight people. Why, our objector continues, can’t a transgender person

be similarly mistaken? The fact that a transgender person is making reports

in line with her neurological development does not establish that she cannot

be incorrect.

But the analogy between people who are anorexic and those who are

transgendered breaks down when we consider the respective goals of the two

relevant parts of the brain. The part of the brain that regulates body weight

exists so that a healthy weight can be maintained. There is a range for

healthy body weight that is the norm; someone with anorexia wants to

achieve a body weight that will lead to electrolyte imbalances that can be

fatal. Thus in anorexia, subjective perception is clearly at odds with proper

function of the human body. On the other hand, the part of the brain that

contributes to the perception of gender doesn’t regulate anything, but exists

just for psychological identity. One can survive, and even reproduce, without

having any gender identity at all.

I am not arguing that introspective reports of sex are infallible. But

according to some studies, a majority of people who undergo sex

reassignment surgery are happy with the decision. There is a real danger of

misdiagnosing someone as transgender and doing surgery that does them

harm, and conservatives have been correct to raise this concern in the face of

those who are prepared to affirm every request. In giving the impression that

this is a decisive reason against every desired sex-reassignment surgery,

though, some conservatives have overstepped. Trying to change a legitimate

self-perception of gender also does harm.

Jennifer Gruenke is professor of biology and director of the Hammons

Center for Scientific Studies at Union University.