language, trans

That Post About Biological Sex

Content Notice: discussion of bodies, genitals, surgery; anti-transgender and anti-intersex bigotry; biologic essentialism

So, a few days ago, I said I would write a post about biological sex. This is that post.

The term “biological sex” has about 15 different meanings, depending on who one talks to and ranges from completely meaningless or unquestionable gospel, also depending on who one talks to. I am not going to rehash all those debates here because a) there isn’t enough space and b) it’s not good for my mental health to trawl through right-wing, anti-transgender websites to look for what people who hate me think about biological sex.

But, so that everyone is on the same page about what sex in the sense of male/female/other categorization is, I think the definition that the UCSF Center for Excellence in Transgender Health provides is helpful: “Sex: Historically has referred to the sex assigned at birth, based on assessment of external genitalia, as well as chromosomes and gonads. In everyday language is often used interchangeably with gender, however there are differences, which become important in the context of transgender people.”

With that out of the way, I want to talk a little bit about my own positionality before I get into the meat of my argument. I’m a transmasculine nonbinary person who’s on hormones and has had some surgery. I am not intersex, to my knowledge. My body does not fit into traditional male/female binary sex system. I do not intend to speak for all trans people, I cannot speak for all trans people, and I encourage anyone who reads this to seek out the perspectives of other transgender, nonbinary, agender, and intersex people of all genders on this issue.

With that, I’m going to try and tackle my thoughts on this issue.

Julia Serano, a transgender woman who holds a Ph.D. in Biochemistry and Molecular Biophysics, writes this in her essay Transgender People and “Biological Sex” Myths: “While there are a number of sexually dimorphic traits — such as chromosomes, gonads, external genitals, other reproductive organs, ratio of sex hormones, and secondary sex characteristics — many times these traits do not all align (i.e., all male, or all female) within the same person, as is the case for intersex and many transgender people.” (Links within the quotes are Dr. Serano’s.) I largely agree with Dr. Serano’s evaluation of the issue, although there isn’t much to disagree with: it is an observable fact that traits we use to create biological sex are not always binary in every person.

My thesis, based on the structure Dr. Serano poses, is that a) an easily discernible binary system of biological sex does not exist in any appreciable way and b) trying to shoehorn a wide variation of biological characteristics into a binary system of sex for simplicity’s sake is at best exclusionary and at worst outright harmful to certain segments of the population. I do not mean to argue that certain biological characteristics (e.g., genitals, hormone levels, chromosomes, secondary sex characteristics) do not exist or that these things do not play an important role in health care. I am not disputing the existence of people’s bodies. I am disputing the construction of a binary system to describe a group of phenomena that are, at best, bimodal.

When we speak of characteristics that can be used to “determine” and assign biological sex, we usually speak of five different types: external genitals, internal reproductive and sexual organs, (sex) chromosomes, predominant (sex) hormone(s), and secondary sex characteristics. All of these things are important in determining appropriate medical care for a person but, crucially, none of them determine gender or should be used alone to assign sex. A person could have a binary presentation of some of these characteristics but not others and that person would not be easily fit into a binary male/female sex designation.

The issue I take most with how we have socially constructed1 sex as an infallible binary (and then slapped the label “biological” on it to make it sound more reputable) is that no definition of biological sex is logically consistent with a binary, observable in any easy and meaningful way, and takes into account people’s innate sense of self and identity.

For example, a 35-year-old cisgender woman who has had a bilateral salphingo-oophorectomy and total hysterectomy as part of cancer treatment might have a vagina, breasts, and XX chromosomes, but lack a uterus, cervix, Fallopian tubes, and ovaries, along with the ability to produce the necessary levels of estrogen and progesterone or menstruate. This woman (let’s call her Barbara) could not technically be called “biologically female” because she is lacking some of the traits we associate with “biological female-ness” (e.g., a uterus, dominant estrogen levels, and menstruation) but nobody would deny, as long as Barbara confirms it, that she is both a woman and “female.” It would be absolutely ridiculous to tell Barbara that her cancer surgery has rendered her somehow less female, especially because she cannot be classified as “male” or, frankly, “intersex.”2

Or, as another example, take Eduardo, a 50-year-old cisgender man who works in a chemical factory and is exposed to chemicals that cause a hormone imbalance resulting in gynecomastia, or development of significant breast tissue in men. Eduardo now has what we would generally term “female” secondary sex characteristics (breasts), but that does not make him any less male.

I have used Barbara and Eduardo, fictitious cisgender characters, as examples specifically so as not to provoke controversy. Both of them have some bodily characteristics consistent with how they would identify their own sex and others that are not. While one could argue that because Eduardo (and potentially Barbara) is “biologically” his/her identified sex, even with characteristics that fall outside of this category because most of the characteristics fit, I cannot think of a neat way to draw the lines so that we could clearly delineate who can be “male” or “female” based on the characteristics they have. Some particularly virulent anti-transgender people will demand every single characteristic match, right down to the hardly observable chromosomes. Some people, who take the much more sensible approach of really not giving a shit about other people’s bodies unless it impacts them directly and imminently, shrug and go “I dunno, it’s not my problem, it’s whatever you say” and then don’t really care if Eduardo has breasts because he says he’s a man and he presents as male and that’s really it, right?

It’s also important to note here that the churning on of time and biology (actual biology, not social categories we’ve chosen to call biology) affect bodily characteristics relevant to “biological sex,” too. A cisgender woman who has reached menopause and no longer menstruates is missing a component of the “female” biological sex designation that many consider key. Nobody but the most logically inconsistent of jackasses arguing on the internet would contend that this woman is no longer biologically female because she has reached menopause. Furthermore, young children who have yet to reach puberty do not have many of the secondary sex characteristics we use to guess at sex in adults and are quite androgynous, aside from personal grooming and clothing. Yet we do not argue that pre-pubescent children fall into some nebulous “other” category of biological sex.

A common anti-transgender (and by its nature, anti-intersex) argument is that sex is determined by characteristics at birth: genitals, chromosomes, hormone levels. Leaving aside the obvious rebuttal that not everyone falls into a clear male/female binary of these things when they are born3, very few other characteristics at one’s birth maintain the same amount of social (and sometimes legal) significance. I suppose that I was born with blue eyes and blond hair, and my driver’s license and passport say that I have blue eyes and blond hair (it’s more of a light brown now, but that’s not the point), but my birth certificate contains my height and weight at birth, as well as where my mother and father were born, and a fair amount about the hospital I came into this world in. This information, outside of very specific contexts, is not important. If I am applying for a visa for another country then yes, maybe it is important for that government to know that my father was born in Michigan, my mother in California, and I in a hospital in the throbbing circuit board heart of Silicon Valley. If a doctor wants to run genetic testing on me then yes, it may be important to know what sex I was assigned at birth. The only issue here is that, unlike the unchanging record of where my parents were born, I can and have changed my assigned sex and name on my birth certificate. And, unlike the information about my birth height and weight, there is no spot on my birth certificate stating what genitals or chromosomes I had at birth.

My reaction to “okay, so you can change your name, appearance, genitals, hormone composition, etc., but you’ll always have [whatever] chromosomes” is very much the same. This information is usually not available on legal documents (nor should it be, quite honestly) and is irrelevant to basically any interaction outside of specific ones at a doctor’s office. I don’t even know what my sex chromosomes are – I have never had a karyotype and if one was performed on me before I was born, I’ve never seen the results. Nobody who looks at me can tell my chromosomes from my appearance. Certainly, chromosomes and DNA direct production or formation of things like sex hormones facial structure, and genitals, which have an impact on appearance. But – and this is crucial – those are things that can all be changed. Natural hormone production can be overridden with hormone replacement therapy and, if necessary, hormone blockers; facial structure, chests, and genitals can all be reshaped through surgery (or, in some cases, hormones alone). Despite the blustering of anti-transgender and anti-intersex bigots on the internet, none of them are using karyotypes to detect us.

An argument that Dr. Serano addresses, and one that she is imminently more qualified to refute than I am because of our lived experiences, is that (cisgender) women are oppressed on the basis of biological sex, not gender, and because of this, biological sex matters. E.g., cisgender women face discrimination in accessing abortion and pregnancy care, pay out of pocket for menstrual products, and have the brunt of contraception thrust upon them, so clearly misogyny is sex-based, not gender-based. I will let Dr. Serano speak for her experiences with misogyny and sexism as a trans woman:

While it is true that some forms of sexism specifically target female biology (e.g., slurs for breasts and vaginas, attempts to regulate women’s reproductive systems), many other expressions of sexism target traits that fall under the realm of gender (e.g., accusations that women are not mentally or constitutionally fit for leadership positions, comments deriding feminine gender expression, etc.).

Additionally, trans women do experience many forms of sexism that target female biology — in my case, I have experienced slurs targeting my female body parts, sexual harassment, attempted date rape, men ogling and objectifying my body, and so on.

Furthermore, in my own experiences as a transmasculine person, many “sex-based” discriminatory experiences that fall into misogyny or sexism apply to transmasculine and/or assigned female at birth people. Trans men do not get to opt out of buying menstrual hygiene products, nor are our copays on Pap smears, contraception, and pregnancy/abortion care somehow spirited away because of our gender.4 When we do face these inequities, we are often excluded from the conversation about righting them because they are seen as women’s issues (i.e., gender-based) and we are men with no claim to them, especially if we reliably “pass” as cisgender men. Between Dr. Serano’s experiences and mine, it seems as if cisgender people (and especially anti-transgender cisgender women) flip-flop with no consistency as to whether certain experiences of misogyny and sexism are “sex-based” or “gender-based,” based on which trans people they would like to exclude from discussion of these issues and deny the lived experiences of.

I have no doubt that, despite me trying to be as clear as possible in this post, someone could still read it and believe I want to deny the existence of differences in bodies; that I believe that we should abolish labels, sex, and gender entirely; or that I do not want to hear cisgender people talk about their bodies and bodily issues. I will address these herein:

I do not deny that there are differences between bodies. To do so would be an inane argument; it is easily disprovable. One of the specific reasons I argue against the notion of biological sex is that my body is different than most and I feel that any system of trying to categorize biological sex cannot and will not take people like me into account. Humanity is too diverse in body and mind to try and reduce ourselves to an either/or system, even if most people generally fall into this system.

I do not want to abolish labels, sex, or gender. I want to de-emphasize those things on a societal level. I want people to have the freedom to define their own gender, to use the words and labels that feel right for them, and to refer to their bodies in whatever way they like. Labels are tools: I believe we should use sex and gender labels like a fine needle to sew up small, delicate problems on an intimate, individual level. Right now, I see sex and gender labels as a hammer being swung every which way, hitting and hurting anyone in its path. Clumsy metaphors aside, labels are amazing descriptors, but forcing people to use labels that don’t accurately describe their experiences is ridiculous.

And, finally, the argument that I do not want to hear cisgender people talk about their bodies. I find the bodies and stories of cisgender people no more repulsive than those of anyone else: that is, there is a time and place for every story. I do not want to hear some of the stories cisgender people have to tell about their bodies, just like I do not want to hear some of the stories transgender, intersex, and non-binary people have to tell about their bodies. There is an insidious assumption in many anti-transgender arguments that being transgender is inherently adult, sexual, pornographic, or inappropriate and therefore any trans person who speaks publicly about being trans will therefore be okay with hearing adult, sexual, pornographic, or inappropriate stories from cisgender people, even if they have nothing to do with the topic of hand.

A corollary to this argument,  which I mention here because it is similarly insidious ad similarly inane, is the assumption that transgender people are somehow triggered by cisgender people talking about their bodies and that the mere mention of something like a cisgender woman talking about her experiences at the gynecologist will send trans people running in screaming fits. This argument often ignores all context, such as examples where an anti-transgender cisgender woman invades a conversation held by trans people, tells some story that is ridiculously inappropriate and clearly designed to spark outrage, and then gloats about how delicate and easily upset trans people are when someone inevitably tells her to fuck off. There is a time and a place for every conversation, again, and if a trans person objects to a cisgender person telling a story that is highly inappropriate for the topic at hand, that is not an indictment of trans people.

The rebuttal to all of the arguments against a cohesive idea of biological sex is often that Eduardo and Barbara, along with transgender and intersex people, are outliers whose inability to fit into one neat binary category or another is caused by a mistake, a malfunction, a tragic accident, or something else that can be ignored because it doesn’t happen to very many people. This “logic” is also often applied with the added argument that because there are so few of us, percentage-wise, the binary system works and doesn’t need to be changed to account for a few outliers.

But small percentages of big numbers are also big numbers. Approximately 1 in 100 people has some kind of intersex condition and approximately 1 in 200 people is transgender. (Note that both these numbers come from research done in the United States, so the numbers may vary worldwide.) If we assume that these percentages do not overlap whatsoever (that no person identifies as both intersex and transgender)5, 1.5% of 7.6 billion people6 is one hundred fourteen million (114,000,000) people. The population of California, where I live, is 39.56 million (39,560,000) people, so that’s a little under three times the population of the most populous state in the U.S.. On a more global scale, 114 million people is a little more than the entire population of Ethiopia, which is around 110 million (110,000,000) people.

Clearly, the argument that “it’s just a few people” is silly. Yes, compared to the amount of cisgender and/or intersex people, the number is tiny. But 114 million people with specific medical, legal, and social needs, as well as, in many cases, the power to vote, are not insignificant. Just like it would be ridiculous to disregard the lived experiences of the people of California or Ethiopia because “there aren’t very many of you compared to others,” it is ridiculous to discard the lived experiences of transgender and intersex people because of numbers.

Of course, the next retort is “well, the people of California and Ethiopia aren’t forcing us to ignore science and reason and change our language,” to which my answer is, I can’t speak for Ethiopia because I’ve never lived there, but California has had ballot propositions to repeal the death penalty and to end limits on rent control, both of which make enormous fiscal sense, and both of which failed. I cherry-picked those ballot measures to make my point, just like misrepresenting arguments against the concept of biological sex cherry-picks what trans and intersex people say to make a point. Furthermore, nobody is forcing anybody to ignore science and reason or change their language – what the vast majority of people who argue against the notion of biological sex are asking is for people to reconsider how they perceive various bodily characteristics, not assume everyone fits into a category of “male” or “female,” and to realize that sex and bodies are not as set in stone as one might think. In short, we are asking people to be more critical of a social concept. That is very different from ignoring anything or demanding anything.

Biological sex is a shorthand. It achieves its usefulness for some by being difficult or useless for others. A court stenographer’s shorthand is not useful to anyone who has not been trained in that form of recording but it is useful to the court stenographer, the transcriptionist, and anyone who may later need to see the transcript. We would find it absolutely ridiculous if, upon asking to see the transcript of a court hearing, a person was handed the shorthand notes, not the decoded transcript, and told “well, this works for most people who need to access it, so tough luck.”

Biological sex can get away with this shorthand because it is useful for most people (at least to a degree) and it allows us not to ask awkward questions. If Xinzhen, a cisgender woman whose bodily characteristics all fall into a “female” binary sex category, tells her doctor that she is female, the doctor can safely assume some things about her. But for anyone who doesn’t meet those same criteria, the shorthand of biological sex is perilous. I cannot say my body falls into a truly binary “male” sex category – but it sure as hell doesn’t fall into a “female” one, either.

Even for transgender people who have not (for whatever reason) taken any measurable steps to transition or change their bodies, binary biological sex categories as a  shorthand are ridiculous. For this population, for whom ideas of sex and gender are fraught with assumptions and potential backlash, getting a full story on how they perceive themselves is absolutely essential. Distilling this to “well, you haven’t transitioned so you’re still biologically X” leaves out any chance for further dialog and may deny the very real experiences of people who have socially (and potentially legally) transitioned and face the realities of that, but have not medically transitioned.

Biological sex, I believe, sticks around as a concept despite its flaws because people are hesitant to change something that they see as potentially useful, even if the alternative is hardly worse. To be presented with a list of body parts and to be asked “check all that apply to you” instead of being asked “what is your biological sex?” would make no difference to most people and would make a world of difference to the people who need it. (It would also save me the issue of having to explain to every new provider I see that they don’t need to run a pregnancy test on me because … forget it, fine, I’m not getting into this.) The National LGBT Health Information Center, taking recommendations from the Joint Commission and the Institute of Medicine, advises doctors to ask for sexual orientation, gender identity, and sex assigned at birth. All these are useful coding tools (as long as “sex assigned at birth” is separated from what identity or body a patient may possess now).

For the rest of us, biological sex has little relevance. Outside of a doctor’s office, a person’s genitals do not have much of a place in everyday conversation. For sexual encounters, yes, people have preferences, but those preferences are specifically about intimate acts concerning bodies and not general conversations. Name me a time where, in a perfectly common conversation over lunch, my genitals and their current configuration would truly matter. I’ll hazard a guess that they won’t.

Biological sex, as a concept and a categorization system, has outlived its usefulness as a euphemism. As adults, we can both have frank conversations about our bodies with providers and also know to shut up about others’ bodies in general conversation. Out of courtesy to people who do not fit into these tightly constructed molds, out of respect for the diversity of bodies and minds on this planet, please, reconsider the term.


  1. “Socially constructed” does not mean the same thing as “not real.” Money is socially constructed: we assign values to certain pieces of paper and metal, we say that one can trade that paper and metal for objects and services that we value similarly, but outside of the social context of a currency, it is useless. Consider: if I took a $10 US bill to, say, Germany, and tried to buy a coffee with it, I would have little luck. Yet we do not say that my $10 US bill or the coffee I am trying to buy do not exist or have no value under any circumstances. Similarly, saying that biological sex is socially constructed does not deny the existence of bodies or characteristics. I have a certain set of sex organs whether I call them male, female, non-binary, or purple elephant jersey. The language I and other people use changes from society and group but the organs still exist and have certain properties. 
  2. For this article, I am going to use “intersex” as a sex designation to refer to people who either self-identify as intersex and/or have a diagnosed intersex condition (e.g., 5-alpha reductase deficiency, AIS, CAH, Kleinfelter Syndrome). There isn’t a good word to refer to people whose bodily characteristics don’t fit into a traditionally “binary” biological sex category (I hesitate to use the word “non-binary,” as not everyone who does not fit into a binary biological sex category identifies as non-binary), so for this article, I am going to try to explain what I mean rather than assign a label to people who fall outside of a binary system and do not specifically identify as transgender, intersex, or non-binary. 
  3. This is an obvious rebuttal but it’s not one I want to dwell on because it is sometimes seen as tokenizing intersex people in an argument that’s usually not really about intersex people. I’m not intersex and so I feel I have no real claim to this argument. 
  4. In fact, for transmasculine people who have legally changed our gender markers to male, getting insurance or any outside organization to pay for “sex-based” care at all can be a nightmare, due to the fact that our claims get rejected for inconsistent gender marker. I have about four different notes in my insurance file with Aetna due to calling over and over and having them make a new note every time one of my medical claims gets rejected for “inconsistent gender marker.” 
  5. Obviously, this is not the case. However, 1.5% is a good reference value and trying to calculate the actual percentage with overlap is outside the scope of this post (and potentially undoable with the current openly available data). 
  6. Taken from the US Census World Population Clock on around 1100 AM on 26 April 2019 and rounded to the nearest 100 million for simplicity’s sake.