Biological Science Rejects the Sex Binary, and That’s Good for Humanity

Science points to a more accurate and hopeful way to understand the biology of sex. By recognizing the true diversity of the human experience, humanity can embrace an expansive and multifaceted way of envisioning and experiencing human nature. This evidence-based outlook is not only far more interesting than the simplistic and incorrect “tallywhacker versus no tallywhacker” perspective, but also more conducive to respect and flourishing.

Starting at the most basic level of animal biology, there are multitudes of ways to be female or male or both. The oceans are filled with species of fish that change from one sex to another midlife, and some who change back again. There are invertebrate hermaphrodites and ladies-only lizards who reproduce by recombining their own chromosomes. In some mammals, females are brimming with testosterone and have large “penises.” In various fish and mammals, males do all the caretaking of infants. And in a variety of species, females are authoritarian, promiscuous, and—yes, Darwin—pugnacious.

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Haven’t read the article but I wonder what the 2nd quote is trying to argue. Other species have weird sexes, what does that have to do with Homo sapiens? We aren’t fish, lizards, or horses.

It also seems to me that for the majority of people who consider themselves belonging to some sort of non-cisgender or non-traditional sex-identity related group, they’re for the most part physically rather “normal” male or females.

Yes people with hermaphrodite or similarly rare and “intermediate” anatomy exist. But to my knowledge most of the people who consider themselves transsexuals(this is what this topic relates to I gather) or whatever aren’t hermaphrodites, so I just wonder what referring to individuals with such unusual anatomies is supposed to prove - when someone who is rather obviously physically an almost prototypical male or female - asserts that they’re not.

There’s an awful lot of misguided arguments on both sides of the sex/gender controversy I’m sorry to say.


Science considers humans to be a dioecious species, and I don’t think there is any real controversy over this. The important distinction is between sex and gender. Those are not necessarily the same thing. Sex is assigned to you at birth and is a fact of biology. Gender is how you view yourself and how you relate to others.

What is good for humanity is a free society where people are free to live their lives as they see fit. My opinion of how someone should view their own gender should matter as much as my opinion of what religion they should belong to. It’s none of my business. It is even better if society can embrace these freedoms and show each other a basic level of respect, such as addressing people how they want to be addressed. We don’t have to agree with each other, just agree to let each other be free.


It’s become a really strange discussion.

I think that at least part of the problem stems from a kind of variant of the naturalistic fallacy. People feel that if they can say that they are the way they are, or behave the way they do, because of nature, then this means that any social/moral judgment which disapproves of them is negated. And so there is some impulse, when people are challenged over their gender expression, to say something along the lines that this is an immutable and real part of my nature, ergo, not open to criticism.

This, however, comes into tension with the fact that many aspects of “gender” are culturally defined. I can be a natural biological male, by virtue of genes and development. But I cannot be a natural middle-class American guy, because most of what goes into that is not biologically determined. That cannot, really, be said to be innately who I “am” but it is certainly the mode of my gender expression. This stuff is always socially/culturally mediated.

And so the very people who insist that sex and gender are not the same thing often blend the two when trying to validate their transgendered status against social objections: they point to nature to say, well, sex is complicated. But transgenderism isn’t about complicated sex; it’s about complicated gender.

I’m not much for the naturalistic fallacy. I think that socially we do best by accommodating and acknowledging how others want to express themselves, gender expression being just one of many aspects of that.

One way I have framed this in my own mind is in relation to the many arguments people have had about whether homosexuality is innate or “chosen.” The merits of that dispute aside, I always think: why should that matter? Hypothetically, if homosexuality were (to be clear, I do not think it is) 100% “chosen” and not at all innate, the silent implication in those arguments always seems to be that, well, then it’s all right for us to declare it to be evil and to treat homosexuals badly. But that implication is, I think, just wrong: it wouldn’t really matter because, as @T_aquaticus points out, “it’s none of my business.” Our moral responsibility to others includes accepting differences, however those differences arise, when those differences do us no harm.

P.S. On a minor note, I find the notion of sex being “assigned” at birth, as people say these days, a bit strange. It seems to me that it is “inferred” at birth from the then-available evidence. “Assigned” makes it sound like somebody made a discretionary decision. Now, the inference can be wrong, of course – Androgen Insensitivity Syndrome or other developmental anomalies can complicate the matter.


Exactly. Those who are unable to let others live their own lives are the ones with the problems. It reminds me of line: “Some people get their kicks from stumping on dream” from That’s life by Frank Sinatra.

That is the way I also regard it. Although at times ambiguous sex is biological and gender is psychological

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At the same time, it is entirely normal for humans to ask someone for someone to justify why they are different from most people in society. It is just one of our human foibles. People shouldn’t be shouted down or shamed for beginning a conversation from that position. Where I think those conversations go off the rails is when people forget to recognize the humanity in other people and forget what it means to be an autonomous person in a free society.

I would also add that there is nothing wrong with family and loved ones making someone’s gender identity their business. Everyone should have people who are concerned about them and make their lives their business. My hope is that people can find support and understanding among their family and friends.




That brings back memories of the 1980’s when a particular Christian psychologist, James Dobson, rocketed to fame as a radio personality and best-selling author of books on raising children and marriage dynamics. He emphatically doubled-down on the “homosexuality is 100% chosen” theme for what appeared to be that same “If you can choose whether or not to do this particular X, then there is no excuse for continuing to do X.” It struck me as very odd that someone with his academic training and clinical experience could somehow totally rule out genetic factors in sexual orientation. After all, psychologists and psychiatrists continually must weigh nature-versus-nurture elements in understanding and treating their patients.

Yet, Dobson didn’t appear to treat other “thou shalt nots” from the Bible in the same “100% chosen” way. For example, he readily admitted that some people have a genetic predisposition to alcohol abuse—but that didn’t prevent him from telling his audience, “You can choose not to abuse alcohol, regardless of your genes.”

Perhaps this popular Ph.D. assumed that an all-or-nothing argument was more easily absorbed by his audience. I also remember him reciting his sarcastic cause-and-effect “recipe” for parents on “How to produce a homosexual child” with tips like these: (1) Maintain a home where the mother is dominating, overprotective, and possessive, while the father rejects and ridicules the child. (2) Make sure the mother rejects her sons solely because they are male. (3) Make sure each daughter feels rejection because of her gender and assumes that only a male identity carries worth.

Dobson repeatedly told his audience, “Scientists have still found no evidence that homosexuality is genetic.” I often wondered what he was going to say when such evidence was eventually published—because even if the data suggested that genetics was only a minor contributing factor, he would risk losing credibility with his audience over an unnecessarily absolutist statement.

Anyway, as you said, bombastic declarations on gender seem to be popular with more than one side in these debates.

Seeing how dioecious rhymes with a great many words, it is really a pity that it is not more common in romantic ballads.

These are normal reasonable responses as opposed to demonizing responses.


I think your dichotomy is nadvertently excluding a lot. “Nature vs. nurture” isn’t “genetics vs. choice”. There are many non-genetic factors involved that aren’t chosen by the individual, pre-natal environment especially. Neither nature nor nurture is chosen.


I’ve already taken a swipe at evangelicals in another thread today, so I might as well just keep it up. Note - I don’t know exactly what I would classify myself as at this point, other than Christian, but I’m probably more evangelical than mainline, Catholic, etc.

I hate to say it, but I’m pretty sure Dobson’s popularity was a huge pat on the back in the form of confirmation bias to that very high proportion of evangelicals that were predisposed to shunning and mistreating homosexuals. Having a PhD psychologist telling people notifying his audience that homosexuals are homosexual because they CHOOSE to be homosexual was a valid license for the bigotry they already felt. It was hugely popular.

That confirmation stemming from the 1980s is alive and well today. My Genetics textbook has a good chunk of one chapter devoted to sex determination of a wide range of animals, but also takes a close look at human sex determination - including several mutations that can lead to non-binary sexual anatomy. Students are always riveted by this stuff, but the father of one of my students called both my Dean and the Provost, upset that I was apparently pushing transgenderism in class. My Dean left me his phone number, which I called. He didn’t pick up the phone, so I left a message explaining what was and was not covered in class. I also emailed the class to make sure they understood what was and was not covered. Unsurprisingly, I never heard back from the father.


I’ve encountered the same thing in both my Animal Biology and Human Biology classes. Last year a student declined to do an assignment on intersex conditions, saying that doing the assignment would be a threat to her faith. She said that she realized that not doing the assignment would affect her grade, which I respected. But I really wanted to say “if learning about actual medical conditions is a threat to your faith, you have bigger problems than this assignment. God help you if you have a child with one of these conditions.”
Since I knew this year was my last year and because it was really a struggle to keep students engaged once they realized they would be transferring, this year I really pushed the limits and talked about gendered behavior in animals. Students who hadn’t said a word all semester asked sone great questions. I got a call from the VP of Academics. My response was “everything I said was factually true.” He decided to drop it, I’m guessing because he had bigger problems to contend with.


Correction. We definitely ARE fish!


And mammals and primates and innumerable other classifications. But I think the point remains. What occurs in other species doesn’t necessarily occur with humans. I assume you’re not swimming around in the Atlantic for a few years only to migrate back to where you first hatched in some river in Canada, lay eggs, and then die. But hey, I like to keep an open mind.


I’m gonna regret getting involved in this thread, but this isn’t true. Sex also has a significant social component. And also, the assignments at birth can be and frequently are incorrect. And also, what about intersex people?


“Fish” is a colloquial paraphyletic group, so it shouldn’t be used in biology if you are aiming for accuracy. The correct monophyletic group would be Craniata if you want to include agnathans like the hagfish and lamprey.

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Yeppers. When I teach this, I always start with Guevodoces syndrome. 'Guevedoces': Rare Medical Condition Hides Child's Sex Until Age 12 | Live Science
That gets everyone’s attention real fast.


I’m probably going to regret getting involved in this thread as well, but… a couple of your assertions seem plainly false to me, and I want to try to understand your reasoning behind them. Could you expand on these further?

“Sex has a significant social component.” How is this the case? From my understanding, sex by definition refers to the type of gametes produced by the organism (or perhaps more precisely, it refers to the proper function of the organism with respect to producing gametes of one type or another). I think we should say there are socially determined differences (in behavior, norms, etc) that get associated with sex, but they aren’t definitive of it. If my understanding here is wrong, in what way?

“[Sex] assignments at birth… frequently are incorrect.” Obviously they can be incorrect, but from everything I have seen on the subject, this assertion puts some strain on the meaning of “frequently”. What do you mean by frequently? How often are sex assignments at birth incorrect?

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I too was curious:

… intersex conditions, defined generally as sex ambiguity or a mismatch between primary sex characteristics and external phenotype, occur in less than 0.02% of people. The fact that some of these individuals are occasionally misclassified does not suddenly call into question the classification for the remaining 99.98%.

The vast majority of transgender people, however, are not intersex and their sex has been recorded correctly at birth. The use of the phrase “assigned male/female at birth” is therefore misleading, as it suggests there may be sufficient reason to doubt whether a trans person has been properly classified and implies their sex has been arbitrarily chosen for them. Neither of these framings are true.


I don’t think this is a good definition because it doesn’t take into consideration conditions where 1) no gametes are produced, and 2) the genitalia do not correspond to a person’s genotype. For example, in Androgen Insensitivity Syndrome, which affects 2-5 per 100,000 genetic males, no gametes are produced and infants are usually identified as female based on genitalia. When a baby is born, sex is determined based on genitalia unless there is some reason not to.
According to Wikipedia (yeah, not the best source), sex assignment is wrong about 0.2% of the time.Sex assignment - Wikipedia.


That’s how the word “fish” is most often used, but I used the word such that it is cladistically accurate, so your argument is invalid :wink: