August 28, 2021

Why are trans people trans? Part 2 ( A Look at Well Known Narratives)

In part 1 of this article I explained why we need to look into what makes transgender people trans. In this part I discuss some of the most influential theories and explain why I think one of them is better than all the others.

The theories attempting to explain trans identities

 I will focus on the four of the most dominant scientific models found during the last 150 years or so:

  1. The Rainbow Model
  2. The Body Trap Model
  3. The Psychodynamic Model
  4. The Two Type Inversion Model
There is also a wide research field addressing gender roles and gender identities in the social sciences and the humanities. Gender studies have, for instance, contributed greatly to our understanding of gender variance. 

But that tradition is most often based on a given acceptance of transgender identities, and is more interested in explaining the way social systems lead to oppression based on gender. It rarely considers the interplay between biology, culture and psychology, which I suspect is the primary concern of Tailcalled, who invited me to this discussion, so I will not describe it here. 

That sort of thinking has greatly influenced my reading of the science of gender and transgender identities, though.

The Rainbow Model

The dominant model for explaining transgender identities these days is what I will call the Rainbow Model. It is a non-reductionistic model, in the sense that it does not reduce sex and gender to a simplistic biological sex binary or one single factor of origin.

Modern research has uncovered a mind-boggling complexity as regards  the development of biological sex, both as applies to the development of the body (both prenatally and after birth) and the formation of a conscious gender identity.

It is not that this approach dismisses the importance of gonads for procreation or argues that genitals are not important. It is simply stating that the number of variables involved in the development of these and other sex traits is so mindbogglingly large, that the development of a human being never follows one and only one norm for what it means to be a man or a woman. 

This approach tells us that the way the people in power assign gender at the time of a person's birth is based on a superficial view of their biological sex (they normally look at the genitals only). Moreover,  the doctors and the midwives are also likely to ignore the way the development of the mind influences the development of  a gender identity.

If the genitals have been ambiguous, the medical system has – until quite recently – tried to force children's bodies to fit one of the two accepted genders by using surgery. The policy has been to erase intersex variants, so that it becomes easier for the infants to live up to their assigned gender and – I suppose –  to make sure that people are not made aware of the fact that the binary is fuzzier than their world view tells them.

Within the rainbow model, scientists have actually been influenced greatly by research on intersex conditions. The main line of reasoning is that intersex conditions  are at least partly caused by genetic variations, especially as regards sex chromosomes (as in XXY, XYY etc.). These chromosomal variations leads to variations in the hormonal environment in the womb, which again leads to changes in the development of the body. 

The body's ability to make use of hormones (its hormone receptors), also plays a role here.

It was partly the research on intersex people that caused the creation of the gender concept in the first place. It became clear that many intersex people did not feel at home in the gender the doctors had assigned to them and that they had confirmed with surgery. Whatever caused this gender dysphoria must therefore be found in the brain, scientists reckoned.

David Reimer was reassigned as female after botched genital surgery damaged his penis when he was a baby. The idea at the time was that gender was a result of upbringing, and not inborn. He suffered from intense gender dysphoria, and ended up living as a man. His story was one of many that caused scientists reconsider how gender identity is created.

Based on these insights scientists have argued that the development of the brain is also influenced by such pre-natal conditions, which may explain why a person with a recognizable "male" body may experience themselves as a woman. 

Note that the genitals get their shape in the first trimester of the pregnancy, whereas brain differentiation is believed to start in the second trimester. Different hormones at different times may therefore explain why genitals and gender identities do not develop in tandem.

Few researchers argue that genes represent the only factor explaining transgender identities. Most seem to believe that it is the interaction between genetic, epigenetic, hormonal, social and personal factors that ultimately cause someone to become transgender. 

Tinca JC Polderman and her colleagues have put it this way:

Studies have shown that most complex traits are multifactorial and polygenic, meaning that hundreds or thousands of genetic variants, each with individually small effects, contribute additively to trait variance along with other non-genetic factors.

Given the insane number of variables involved, and the fact that, for instance, hormone  levels are gradual and not binary, we end up with a model of continuums. There are nonbinary identities, and the intensity of gender dysphoria may vary significantly from trans person to trans person.

The Body Trap Model

One very popular model for explaining transgender people is that they have a gendered soul trapped in the wrong body. In modern medicine this approach has been found in research that tries to pinpoint what parts of the brain determine gender identity, both in cis and trans people.

The idea is that there might be a section in the brain that determines gender specific interests, abilities, personality traits and behavior. This will therefore most likely also be the home of someone's gender identity, these scientists believe. So a trans woman is seen as a person with a female brain and a male body. 

The "trapped in the wrong body" narrative works well as a metaphor. The image may capture the horrors of gender dysphoria in a meaningful way. But it has to be seen as a metaphor, and it represents a misleading representation of what really goes on.

One problem is that it has become increasingly difficult to determine what the emotional and cognitive differences between men and women are. During some 150 years of sexology female liberation has challenged the stereotypes over and over again, and continuously pushed the boundaries for what is considered "proper" male and female behavior. 

It turns out that women can do very well at university. They can make excellent politicians, doctors and soldiers. Moreover, as men are allowed to explore their "other" side, it becomes clear that many of them can be as good at compassionate parenting as many women are. 

Yet, in spite of this, many researchers' attempts at measuring "femininity" and "masculinity" are based on gender stereotypes. This means that "mail brain/female brain" models of gender are notoriously unreliable. Because how do you determine that a brain is female, without looking at behavior and beliefs?

Illustration: Jae Young Ju & Crossdreamers
If there are any statistically significant differences between the genders left, they are so small that it is impossible to define what a "female brain" is. I have made note of the fact that Simon Baron-Cohen, one of the most enthusiastic proponents of the female and male brain way of thinking, has to admit that around half of the women he studied do not have "a female brain," as he defines it. At that point the term not longer makes any sense to me.  

It is also hard to pinpoint what it is in the brain that forms the core of such an identity. The brain is a complex organ where the sense of self cannot be located in one and only one region. One should expect this to apply to gender identity as well. If memories are distributed through different regions of the brain, might not that also be the case for gender identity?

Yet, much of the research has been focused on finding specific regions where the brains between men and women differ, and the see if the brains of trans women or trans men are the same as those of cis women and men. This is what I call "the gender chip in the brain" approach. Brain regions that have been explored include BSTc, cordial thickness and INAH3.

There are many problems with this approach, the main one being that they are reducing the complexity of gender to one simple cause. 

Another problem is that regardless of what part of the brain you measure, the researchers are always looking at aggregated data. This means that a lot of cis women – i.e. women who identify as their assigned gender – have "male like" brain regions and vise versa. This means that these regions cannot possibly determine the gender identity of a person alone (although they may, on an aggregate level, be associated with gender). 

It is also hard to determine if the shape  or the size of a brain region reflects gender identity or sexual orientation.

Then there is the problem of the brain being plastic. It changes even in adults. These changes are caused by practice, life experience and learning. So a "female like" brain region in a trans woman may actually be caused by her seeing herself as a female (a circular process, indeed), and a "male like" region may be caused by her being raised as a man. 

A man trapped in a woman's head etc. Illustration: Kemalbas

Hormone treatments may also have an effect.

So does this mean that the brain plays no role in the development of a gender identity? Didn't I just write that the Rainbow Model, which I have sympathy for, does include  biological factors in its explanation for what makes trans people trans?

Yes, I did. But whatever it is in the brain that gives a person a strong and consistent feeling of being of this and that gender, does not have to be associated with specific gender traits. It may simply be a function that compels a person to find acceptance and a life as one specific gender. Given the huge differences in the way cultures define proper gender roles, such a flexibility will help ensure the survival of the individual and the species.

Remember that a lot of cis people, i.e. people who identify as the gender they were assigned at birth, might express interests, personality traits, emotions and behaviors that in their culture is associated with the opposite gender. That does not stop that woman from being a woman or that man from being a man. 

In other words: The behaviors of humans, unlike some other animals, are not programmed by genes and instincts alone. This is probably also the case for parts of  what we refer to as gender. Gender identity is a real and consistent force in human life, while gender roles and expected behaviors are constantly changing.

Even if the inborn part of a gender identity is not defined by gender stereotypes, it still makes sense that trans people feel the need to make use of such stereotypes to express themselves. This is a way to tell other human beings who they are, and to get the affirmation all people need.

Genes and twin studies

In the same way there is not one single gene that makes people gay, there is  not one single gene that makes trans people trans, but twin studies do indicate that there is a genetic effect. 

Siblings of transgender twins are more likely to be trans than those of other people. Still, the fact that not all identical twins of trans people are equally trans tells us that there are other factors in play as well.

Jack and Jace Grafe are identical twins. Both are trans.  One study found that in 20% of identical twin pairs where one twin was trans,  both were trans, compared to only 2.6% of non-identical twins. That is a clear sign of genetic components playing an important role.

I made note of the fact that Tinca JC Polderman & Co, in their literature review (Behavior Genetics 2018) concluded that:

This review of existing family and twin studies summarizes significant and consistent evidence for the role of innate genetic factors in the development of both cisgender and transgender identities, a negligible role for shared environmental factors, and a small potential role for unique environmental factors.

This fits another observation, namely that the cultural and social conditioning is for the most part dominated by a binary understanding of sex and gender, with gender variance often being severely punished. This makes it hard to explain how transgender identities are created without any form of biological component. In spite of what the transphobes tell you: No one chooses to be trans. It is a often a very painful journey, indeed.

I will also point to the fact that hormone therapy most often has a very positive effect on the emotional well being of trans people. There may be a placebo effect at work, for sure, as being given the hormones is in itself a kind of social affirmation. Yet, based on all the feedback I get from trans people, I am convinced there is more to it than that. The effect of HRT on trans people points to a biological basis for gender identity.

So my current conclusion is that the Rainbow Model makes sense, but that the science community has not come up with a complete explanation for gender variance that is solid and unquestionable yet. This is why I, like so many others, simply say that transgender identities most likely are caused by a complex interplay between biological, social and personal factors, and leave it at that.

Part 3 looks at the Psychodynamic model and the Two Type Inversion Model.


Relevant articles found at this site

Other articles


See also Books on Crossdreaming, Sex, Gender and Transgender Lives

Top photo of transgender person: Vladimir Vladimirov


  1. "In spite of what the transphobes tell you: No one chooses to be trans. It is a often a very painful journey, indeed."

    Indeed. A dear gay friend, Tom, patiently and kindly answered my question to him where I wondered if being gay was a choice. After all, in 1980s San Francisco being a gay man looked like fun although not my cup of tea. "No, certainly not," he said. (He passed away of AIDS several years later. I think of him often and miss him.)

    As a young child (5? 6?) I went to sleep at night dreaming about what it would be like to be a girl and how much I wished for it. As this pattern continued I wondered even then if I had simply developed a thought-pattern habit that I needed to break. But, you know, however much I tried I simply could not.

    Gender dysphoria stuck with me for the following half-century of my life until, finally, I bit the bullet and transitioned. What a miracle it is to live authentically. Where I used to ponder a short life now I am excited to be alive.

    Enough about me.

    Absolutely fantastic article, Jack. Man, you've really done your homework. The rainbow model does make sense especially as we have thus far been unable to isolate anything that even partially determines ones sexuality or innate gender.

    If I was a researcher I'm sure I'd be drawn to trying to identify a single brain region that's flipped one way or the other, or maybe has shades of grey that shows a statistical spectrum of identities. Even now as I write this it's hard for me to disabuse myself of that notion. After all, it's the brain, right? !!!

    Anyway, thanks again, Jack. Say hi to Sally.

  2. I was hoping you would mention how sexual orientation also seems to correlate with "typical" gendered expression, behavior and interests.
    Is that in another blog post somewhere?


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