Comment by zz3
4 months ago
Also one more thing of note before you go into "but intersex is just error":
"Errors" are important in models. Look up Type 1 and Type 2 errors. If I had a model for hair color, and it couldn't explain red hair, it would be a pretty terrible model. As I mentioned earlier, red hair and obviously, visibly intersex are about on the same order of magnitude.
To further illustrate this concept, consider humans and horses. You'll notice there aren't human-horse hybrids. We can come up with a criteria or a model to separate humans and horses with 1's and 0's and there's nothing in the middle. That's an example of a binary system. We could come up with a bunch of terrible models too that can't differentiate between the two ("mammals"). But ultimately, I could disprove your argument about transgender in sports even ASSUMING a binary model in sex because it's pretty fundamentally irrelevant. If we can't measure the difference between two things (sports performance between ciswomen and transwomen after 2 years of hormonal therapy), then the difference doesn't really matter. The fact that there's transMEN regularly playing in the Olympics is also fairly revealing.
I think you've missed my key point which is that sex is fundamentally defined by gamete type, and is not a post-hoc clustering of traits. The underlying biological concept is reproduction via anisogamy, which is robust across a multitude of species, humans included. Anisogamy, which you should know as you studied biology, is a reproductive strategy involving the fusion of a small gamete with a large gamete, producing a new individual.
In hermaphroditic species, the two halves of this reproductive system are both embodied in each individual, and are active either consecutively (as with sequential hermaphrodism) or concurrently (as with simultaneous hermaphrodism). In gonochoric species, these are embodied in two distinct classes of individual, via two distinct developmental pathways. Humans are a gonochoric species.
When you claim "sex is a spectrum" or "sex is bimodal", you are confusing sex characteristics with sex. These characteristics are species-specific, whereas sex itself is a cross-species categorization in which sex determination, sexual development, and sex characteristics will vary.
You comment "let's hypothesize that human sex is [always] determined by [XX or XY] chromosomes" and make the argument from this that conditions like Klinefelter syndrome and SRY-negative XY chromosomes disprove that hypothesis. Yes it does, but the hypothesis was flawed in the first place. There is no "human sex" that is different to "sex". More precisely, what you are actually talking about here are the mechanisms of sex determination and sex differentiation in humans. Analyses of DSDs have been very useful in gaining a deeper understanding of these, just as analyses of rare pathologies in other systems do.
Claiming "sex is a spectrum" adds no utility here. It conflates development with definition, and is used for rhetorical ends rather than advancing scientific knowledge. As our conversation has shown, there's not even any consistent understanding of what this spectrum might look like or where individuals should be placed on such a spectrum.
You mention sterility, but this doesn't change someone's sex. The elderly and infertile retain their sex because it's developmental, not performative. This is also why, for example, we can recognize worker bees as female despite them being infertile.
Going back to sports, the available evidence does not show that male athletes weakened through testosterone suppression are equivalent to female athletes. It is not possible to unbuild the body of a human male and rebuild it as female. Your claim that "scientists have already looked into this, and they determined that after two years of hormone therapy transwomen are fairly hard to distinguish from the natural variation in ciswomen for all their metric" misrepresents the research and doesn't take into account what we see performance-wise when these males are allowed to compete in women's sport. Note that while we observe "transwomen" dominating women's competitions, we don't see the same for "transmen" in men's categories, even when they've been on testosterone for many years. This in itself highlights the impact of sex differences in athletic performance.
Let me see if I understand your argument. I'm not sure about several aspects, and it sounds like you have multiple arguments.
[1] Sex is purely defined by gamete size. (Already incorrect, but if that makes the argument easier we can play pretend.) [2] Humans are a gonochoric species. (true) [3] In gonochoric species, unlike simultaneous or sequentially hermaphroditic species, gamete-size generally remains constant throughout the lifetime of the species (also true). [4] Therefore, humans generally maintain the same gamete size throughout an individual’s life (sure, not many people are switching their gamete size throughout their life).
We’re in agreement humans aren’t generally switching gamete sizes through an individual’s lifetime. That would honestly be ridiculous and no one is arguing this. However, while some of these ideas are true and are convenient for talking about various species, it’s not always correct when talking about individuals.
An example of this is using generalized words or labels on anything or anyone. “English-speaking” could mean someone who speaks only English, someone who speaks only a little English. What matters is context and relevance.
Human sexual phenotype can be described by three discrete categories if you want: male, female, intersex. This is what I mean by “spectrum,” I’m literally just mentioning it doesn’t fit the definition of binary (being able to be completely described with 0 or 1 without loss of data). Please see my previous explanation for further details on this. I literally did a proof-by-contradiction.
In individual humans, our genotypes do not always match our phenotypes. For example, XY + No SRY would be functionally identical to XX. XXY and XYY are both viable and happen, and a lot of people might not even realize they don’t have the chromosomes they think they do.
Obviously intersex is about the same proportion of the population as red heads, for context.
So intersex is a perfectly normal and natural human sex phenotype. There are literally human beings living with both gamete sizes for their entire lives, living hopefully happy, healthy lives. This has nothing to do with gonochoric or hermaphroditic species. We’re still a gonochoric species, even if intersex humans exist. Humans aren’t spontaneously changing gamete sizes throughout their lives, but some people literally just have both and have had both since birth. That’s just how it is.
So human sexual phenotypes don’t always match genotypes. They mostly do, probably over 80%, but we’re not honestly sure about the true rate of intersex mostly because it matters so little. As you saw in the textbook chapter I referenced, human sexual phenotype has many factors, but yeah, we can summarize it with three discrete categories: male, female, intersex. That’s again, just how it is. We can debate what to do with intersex, sure, but it honestly doesn’t matter very much.
Your sports argument seems a little strange, I’m honestly not sure I fully understand it:
[1] Gamete size is the only determining factor in human sexual phenotype [obviously incorrect, please see that book chapter] [2] As a society, we divide up sports by sex or gender [yeah, sure, we sometimes do that] [3] Gamete size is relevant in sports [very obviously incorrect, but what you probably mean is that gametes CORRELATE with testosterone, muscle mass differences etc, which is true, and we can measure those correlations] [4] People can’t change their gametes [no one is talking about this, ridiculously irrelevant] [5] Therefore people can’t change their sex?
Trans people exist. We have accepted that there is both biological sex and gender (social construct). Just like genotype and phenotype, they normally match, but sometimes they don’t. I honestly don’t understand why there’s any upset about this, there’s been evidence of this going back pretty far throughout history. We literally get the word hermaphrodite from the ancient Greeks.
So do you only care about transpeople because of sports? There are transmen in the Olympics, so I think they’re doing fine, and I literally linked several papers on transwomen in the Olympics, but I can link them again.
We’ve measured it. This is what science does.
More links: Sex differences and athletic performance. Where do trans individuals fit into sports and athletics based on current research? https://www.frontiersin.org/journals/sports-and-active-livin...
SPORTS AND PERFORMANCE IN THE TRANSGENDER POPULATION: A SYSTEMATIC REVIEW AND META-ANALYSIS
https://www.scielo.br/j/rbme/a/CDkTksYcMPcKYTHGfcJLX4K/?lang...
Transgender Women in the Female Category of Sport: Perspectives on Testosterone Suppression and Performance Advantage
https://link.springer.com/article/10.1007/s40279-020-01389-3
Honestly, if there is some advantage, they’ll measure it, try to understand it, and then change the rules. I’m sure it’s an ongoing discussion. I’m not sure I see your point with all this.
> We have accepted that there is both biological sex and gender
This is close to the real point of dispute, on which there are approximately three main positions, which amount to two political camps because the last two positions drive the same political conclusion (and can be hard to distinguish):
(1) Sex, socially-ascribed gender, and gender identity are real and distinct things, all of which are (or in the case of active gender should be) multidimensional spectra though they may have something like a bimodal distribution which can naively look binary, and normatively ascribed gender should be aligned to gender identity;
(2) Sex and ascribed gender and gender identity are real and distinct things, the former is a crisp binary defined by particular physical traits (which traits varies among holders of the belief and over time; gross anatomy was popular, combination of X & Y chromosomes was popular, gamete size is currently the most popular), and normatively both ascribed gender and gender identity should conform to sex; when gender identity specifically does not it is a kind of mental illness, that should be treated and corrected, not accommodated and validated;
(3) Sex and ascribed gender are real and distinct things with the nature and relationship described in #2, but gender identity does not exist and is a myth invoked to excuse personal moral deviance and/or sexual perversion.
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I think you're still missing several key points. Biological sex is more than just gametes. This isn't some weird, niche theory, this is just basic biology. Even if it were just gametes, there are still several intersex conditions. The data is not inherently binary, we measure models by their outputs. This is a common misunderstanding from those not very familiar with how models are used in science and math.
> You comment "let's hypothesize that human sex is [always] determined by [XX or XY] chromosomes" and make the argument from this that conditions like Klinefelter syndrome and SRY-negative XY chromosomes disprove that hypothesis. Yes it does, but the hypothesis was flawed in the first place. There is no "human sex" that is different to "sex". More precisely, what you are actually talking about here are the mechanisms of sex determination and sex differentiation in humans. Analyses of DSDs have been very useful in gaining a deeper understanding of these, just as analyses of rare pathologies in other systems do.
I'm literally talking about human sexual phenotype. That's it. Phenotype does not always match genotype, that's the whole point. Do you understand the difference between genotype and phenotype, because that's half the point of what I've been discussing. You've also missed my entire point about how we measure models in science and what a model is. That whole demonstration was to show you how we actually test models in science.
> Claiming "sex is a spectrum" adds no utility here. It conflates development with definition, and is used for rhetorical ends rather than advancing scientific knowledge. As our conversation has shown, there's not even any consistent understanding of what this spectrum might look like or where individuals should be placed on such a spectrum
I'm not claiming anything. Human sexual phenotype is not binary, as demonstrated through a binary model with proof by contradiction. This is how we evaluate models. Even if we assume a binary model, as I've mentioned, it doesn't actually matter much since there isn't a huge difference between the two genders for most sports. There are measurable differences for others, but that has nothing to do with gamete size and everything to do with different levels of hormones like testosterone, estrogen et cetera, not gametes. Once again, there is significant overlap between the two sexes to start with.
> Going back to sports, the available evidence does not show that male athletes weakened through testosterone suppression are equivalent to female athletes. It is not possible to unbuild the body of a human male and rebuild it as female.
I'm honestly baffled by this statement. No one is "rebuilding" anyone or anything. I'm not actually sure what you mean by this, but this just further demonstrates that we've moved very far away from anything like science. This just sounds like a strange straw man. If you can't even acknowledge that genotype can be different from phenotype, then there's no point in further discussion, this just seems silly.
> Going back to sports...
Men and women have a lot more overlaps than differences. This has been demonstrated. It was actually surprising to me when I first learned about it. We literally do see plenty of transmen in the Olympics, so I'm not quite sure where you're getting this from. Yes, there are differences too, but again, it has nothing to do with actual gametes and mostly it has to do with testosterone and possibly different forms of estrogen etc. What you're calling "sex characteristics."
Here are a few papers: Sex differences and athletic performance. Where do trans individuals fit into sports and athletics based on current research? https://pmc.ncbi.nlm.nih.gov/articles/PMC10641525/
Effect of gender affirming hormones on athletic performance in transwomen and transmen: implications for sporting organisations and legislators https://bjsm.bmj.com/content/55/11/577?ref=goodoil.news
Transwomen might still be a little faster than ciswomen at least a year after hormone therapy, but most of the other metrics were within normal variation after 1-2 years hormone therapy.
Sexual reproduction certainly does involve more than just the gametes themselves, but the definition of sex is based on gametes - and that they comprise two distinct classes of cell, in size and form. Otherwise, in gonochoric species, how would anyone know which sex characteristics are female and which are male, and how the female and male sex development pathways differ? And in hermaphroditic species, which anatomical and cellular structures correspond to the female and male halves of the reproductive system. It all comes back to anisogamy. This is the fundamental definition of sex.
Regarding your second point: that there are variations in phenotype, some of them disordered, doesn't mean that "sex is a spectrum". For DSDs, we can describe them in terms of specific developmental differences compared to normal sex development. These are a set of discrete conditions that can be understood without conjuring up ill-defined spectrums. In fact, DSDs in humans have given those who study developmental biology considerable insight into the mechanisms of human sex development more generally.
I see after reading those papers you linked that they further illustrate the point I made earlier: that suppression of testosterone weakens males in some ways, but they still retain physiological advantage from testosterone-driven development earlier in their lives. To advocate for the inclusion of such males in female competitions is to advocate for female athletes to compete at a disadvantage.
If you look at the world records for pretty much every sport, the difference between female and male athletes is very clear. That there exists some overlap between weaker-performing male athletes and higher-performing female athletes doesn't mean that male advantage is significant in almost all sports, especially in ones more reliant on raw strength, such as weightlifting.
You mention the transmen who compete in the Olympics. This is true but they are competing against other female athletes, e.g. Hergie Bacyadan in the most recent Olympics, competing in women's boxing (and in that same Olympics, two males - controversially - won gold, in two other women's boxing divisions). None of them would even come close to qualifying against elite male athletes.
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