What Gender Is My Brain? The Dangerous Phrenology of “Brain Sex”

Home LGBTQIA+ What Gender Is My Brain? The Dangerous Phrenology of “Brain Sex”

History raises cause for concern about the stakes associated with relying upon brain imaging to dictate the source of transgender identity.

By Alex Verman

When POSE actress Indya Moore tweeted about a “biologically female penis” in February, it created exactly the kind of reaction you might expect.

The replies to her tweet are gleefully cruel, mostly condemning her as completely irrational and unrealistic. They reflect a common trope in how the right — and even many liberals, progressive or otherwise — respond to transgender people. In their words and minds, our claims we may have the right to feel and to act as our genders, but that doesn’t make it scientifically true; facts, so the saying goes, don’t care about our feelings.

I couldn’t help but think about this concept when observing the reaction to Moore’s tweet. Even those who sought to defend Moore from her detractors did so by invoking so-called scientific evidence of transgender identity. One Pink News article shared a quote from the lead author of a 2018 Sao Paolo Medical School study, which used brain imaging to claim that transgender people’s brains are particular and identifiable. He suggested that the “differences” between transgender and cisgender brains may occur during gestation — lending support to the idea that trans people are basically “born this way.”

That study from the Sao Paolo Medical School came out within months of a conference paper presented by a Dutch and Belgian research team. In that paper, researchers used brain imaging scans to test the volume and activity of transgender subjects’ brains as compared to cisgender subjects. According to their findings, the brains of transgender women looked and acted like those of cisgender women, compared to cisgender men.

It’s indisputable that “science” as a method of determination and inquiry is a moral good. But beyond “science” as the pursuit of knowledge through rigorous, replicable, and verifiable means, it also operates as a call to authority. Scientific knowledge, and the ability to bolster the legitimacy and sway of one’s claims on that basis, is not apolitical. Throughout its history, liberal political and authority figures have grounded their claims in an exclusive knowledge of truth and reason. The dominant intellectual currents of the Enlightenment and modern turn in Europe stressed an earned objectivity as the only pure source of knowledge, even before the development of an actual scientific method. In the book Black on Both Sides: A Racial History of Trans Identity, C. Riley Snorton explores how such important scientific advances as the development of modern gynaecology, for example, took place through and with repeated experimentation on enslaved Black women. For generations, European and American medical researchers in the 19th century used the scientific discourses of comparison and categorization to insist upon intrinsic racial difference, arguing that something about Black people made them fundamentally different than white people at the biological level. And as disability justice activism warns us, a willingness to cede all authority to those who claim scientific knowledge frequently opens up space for abuse within systems (such as mental institutions) where those marked for “treatment” or “cure” are robbed of agency over the basic rhythms of their lives.


I talked about this with Zoé Samudzi, a scholar of medical sociology at the University of California, San Francisco. She’s concerned that using brain sex diagnoses might have the effect of narrowing access to transition-related care by increasing barriers to diagnosis. Given that we live in a world dominated by cissexism (as well as other forms of oppressive power), there’s no reason to trust in cisgender institutions and researchers to create the conditions for easier transition.

“Science and objectivity are the subjectivities of power,” said Samudzi. “The brain sex studies coming out now aren’t unique things to be debated in themselves: they’re a part of an extended body of literature that tries to biologize experiences of sex and gender which are both socially constructed phenomenon.”

As she puts it, the idea of “brain sex” might be used by gatekeepers to formulate or further enforce the script of what a medically acceptable trans narrative that would make someone viable for transition, such as the common trope of being “trapped in the wrong body.”

Another problem with this work is that it takes the very idea of biological sex as something objective in its own right — natural, inevitable, and separate from the social construction of gender. According to Anna Swartz, an independent researcher and bioethics specialist, this is a tremendous error. In the case of brain sex, the very practice of researching, measuring, and identifying what we perceive to be differences between male and female brains presupposes that “male” and “female” are discrete and purely biological categories that exist independently of cultural or social context.

As Swartz puts it, there’s a noticeable gap between the actual evidence this research uncovers, and the social claims that they appear to make and legitimize. The fact that we’ve taken sparse imaging of a pattern in transgender people’s brain chemistry as evidence of some form of inherent, biological “trans-ness” says more about how we misunderstand the scientific process than it does about trans identity or experience.

“What has received little to no attention, in both scientific and popular media circles alike, has been the degree to which contemporary fMRI research on transgenderism reflects a particular problematic and misleading research paradigm—one that seeks to understand sex/gender differences through the brain,” said Swartz via email.


She argues that, while this proposition may be intriguing, it’s also not well-founded. This line of thinking takes as given that there is an essential, intrinsic difference between genders that can be located in the body. The brain is only the most recent site of investigation: past research has put emphasis on the endocrine system, chromosomes, or the genitals.

But as biologists continue to encounter variation between humans on all of those fronts, the central premise gets more and more shaky. While it’s definitely possible to look at broad categories and differentiate them on the basis of genitals, secondary sex characteristics, hormones, and chromosomes, we’re still dealing with ideal types rather than uniform standards. Hormonal changes occur throughout life and often vary based on environmental factors; genital size and shape and function is so varied that it’s hard to truly put the majority of the world into firm boxes; and chromosomes are poor indicators of how people actually enact their genders out in the world anyway (not to mention the fact that chromosomal variation is widely documented). Essentially, while it’s certainly true that there exists general sexual types, it’s also true that these types are not static, consistent, or biological. At best, what we call male and female are sets of traits that are as much determined by society as they are by biology.

Don’t get me wrong, I am not anti-science, and I don’t think transgender people should reject science as a way of living in our identities and bodies. And when I critique science, I’m not doing it in the same way that climate change deniers or evangelicals do. Rather, I am a student of history, and history raises cause for concern about the stakes associated with relying upon brain imaging to dictate the source of transgender identity.

These brain sex papers, and others like them, have had a somewhat mixed reception. Some see them as positives, arguing that their claims are basically good and politically useful. If our identities as trans people can be mapped and spotted early on, then it might help us push back against institutional opposition to trans rights. This way, we have recourse in the hard sciences of neurobiology to demand recognition and respect, especially within the medical system. Rather than rejecting transgender identity as simple delusion, there’s room for us to illustrate our needs and circumstances as a biological reality. It’s a handy response to all those who dismiss our experiences as unscientific and our identities as irrational.

But I worry that this will not have the intended effect. In fact, I see these brain sex studies as a dangerous extension of an already troubling liberal practice. At best, its logical conclusion would only serve to restrict access to transition-related care for already marginalized trans people. At worst, it turns back the clock on decades of trans activism, feminist organizing, and anti-racism work, empowering the darkest discourses among the reactionary right and liberal centre.

Alex Verman is a writer and researcher who lives and works in the territory of the Dish With One Spoon wampum belt covenant. Alex’s work deals with the politics of identity and narrative; they have been published in This Magazine, Teen Vogue, CBC News, and elsewhere in Canada and the United States. You can follow them on Twitter @misgenders.

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