Biology

[Whatevszz]

Sorry if this has already been covered, but I am relatively new to the debate re transgender and self Id etc. My understanding based on biology 101 is that sex is innate (for 99.9% and based on biologically observable criteria such as genitals, chromosomes etc) and gender socially constructed...

However just read this comment online and now I am confused because it might be about 'hormones in the womb' which no-one can really ever know about, can they?? Or am I just succumbing to willful obfuscation of facts?

From here: (comment 22) quillette.com/2018/03/30/plea-trans-activists-can-protect-trans-rights-without-denying-biology

Hugh Easton 31/3/18
`Science is clear. There’s a popular, but mistaken, belief that sex is determined by X and Y chromosomes. In fact, all being XX or XY does is determine whether you develop ovaries or testicles. Everything from that point onwards is driven by hormones. Because hormone levels are not binary but exist on a spectrum, sex itself isn’t binary but exists on a spectrum too.

The vast majority of people do develop ovaries or testicles at the appropriate point in embryonic development, and for most people those organs produce their hormones as they should throughout the time their prenatal development is taking place. That’s why the majority of the population fall into an easily defined male or female category. However, for a minority of people, things don’t go according to plan, and they have hormone levels outside the range for their genetic sex for part or all of their prenatal development. In that situation, you end up with people with a mixture of male and female characteristics (or in some situations are even completely the opposite physical sex to their genetic one).

Historically, medicine has looked at intersex purely in terms of genitals. However, in reality, sexual dimorphism extends throughout the body, including the brain. Animal studies show that there are hardwired differences between male and female brains, that arise before birth and drive most of the differences between adult male and female social and sexual behaviour. As with other aspects of sexual development, the factor that decides whether you develop a male or female brain is hormone levels during the time brain development is taking place.

In human beings, the critical period when the sex differences between male and female brains are thought to arise is during the second half of the pregnancy. This is long after the critical period for genital development, which starts about 7 weeks after conception and has largely finished by the end of week 12. Therefore it’s possible to have people whose genital development has taken place in line with their genetic sex, but whose brain development has taken place as the opposite sex. All it takes is for something to disrupt foetal hormone levels during the second half of the pregnancy. The available evidence points to this being the underlying cause of being transgender.

The personal experiences of myself and others, whose mothers were given hormones during pregnancy for miscarriage prevention or for various other medical reasons, also bear out the importance of hormones in determining the sex of your brain (and suggest that a large number of transgender people are probably like that because of doctors administering hormones during pregnancy).*

This is quite a straightforward article:

news.cnrs.fr/articles/how-many-sexes-are-there

"Whatever their origin, all of these anomalies show that intersex traits cover a vast range of biomedical conditions varying in frequency and severity, and that the precise number of different biological sexes among humans is in reality a complex issue. It is generally held that there are no simple answers to this question.

Based on the sole criterion of production of reproductive cells, there are two and only two sexes: the female sex, capable of producing large gametes (ovules), and the male sex, which produces small gametes (spermatozoa)."

However, this gonadic criterion (based upon reproductive glands) is not the only factor on which the definition of biological gender rests. We must also consider genetic sex (based on X and Y chromosomes), anatomical (based on the appearance of the genitalia), hormonal gender (based on the predominant hormones), and so on. Moreover, “each sexual parameter can have variants,” explains Éric Vilain, of the Epigenetics, Data & Politics Laboratory.4 For example, “XX/XY mosaics” are individuals with gonads comprising both ovaries and testicles. We may thus conclude that an infinite combination of biological genders exists... and thus, far more than the five sexes proposed by Anne Fausto-Sterling in the 1990s, which were in fact based primarily on a gonadic definition of gender.”

So is there really a practically unlimited number of biological sexes? Not according to Vilain, in any case: “intermediate states between the different biological sexes are extremely rare and often associated with infertility, which in evolutionary terms consigns them to a dead end,” says the researcher. “It is not reasonable to place the two biological sexes present in the vast majority of cases on the same level as the extremely rare intermediate sexes.”

This is where definitions become important.

Sex and gender are not the same thing.

Humans are a sexually dimorphic species. Sex refers to how we reproduce. If you are male you have an X and a Y chromosome while females have two X chromosomes. With the caveats clearly described above about intersex people.

Gender is separate, less well-defined. It refers to your own perception of your maleness or femaleness and whether this matches your physical sex, and is quite possibly a spectrum. I really struggle with this as I don't have a feeling of being female, but I acknowledge that others do have that feeling and that sometimes, this doesn't match their physical sex - referred to as gender dysphoria.

I have done a little bit of reading of the science literature on the physiological basis for the feeling of gender (skim read a couple of papers), and there appears to be some good evidence for brain differences in people with gender dysphoria; however, these are not sufficiently established to be useful for diagnosis. IDK if transgender people would welcome a diagnosis in this way or not if it were available anyway.

You can clearly distinguish differences between male and female brains using modern scanning techniques. Those studies that have reported additional differences in the brains of trans people generally still place them in the category of their chromosomal sex (i.e. male to female transexuals have brains most similar to men and vice versa).

The definition of trans used in most contexts appears to be broadening hugely of late though. Stonewall defines trans as follows:

"an umbrella term to describe people whose gender is not the same as, or does not sit comfortably with, the sex they were assigned at birth. Trans people may describe themselves using one or more of a wide variety of terms, including (but not limited to) Transgender, Transsexual, Gender-queer (GQ), Gender-fluid, Non-binary, Gender-variant, Crossdresser, Genderless, Agender, Nongender, Third gender, Two-spirit, Bi-gender, Trans man, Trans woman,Trans masculine, Trans feminine and Neutrois."

Not all of these people will have gender dysphoria as it is defined for the purposes of sceintific studies of its physical basis, which will have involved very clear cases of dysphoria.

The basis of the law on sex as a protected characteristic is clear and based on chromosomal/reproductive sex.

Gender is poorly defined and self ID would make it even more so.

I don't think there is any debate on whether gender dysphoria exists. It quite probably has a physiological basis.

My questions are:
How many trans people have gender dysphoria?
Which definition of trans are people self-identifying into?

There is no evidence that transgender people can change sex as defined above. Hence a transwoman will still also always be male and the transwomen are women mantra is a kindness at best and and Orwellian doublespeak at worst.

@flowersonthepiano

Regarding the differences between the brains of men and women: there are indeed physiological differences between the brains of the two sexes due to the different size of men and women and the effect testosterone has on physiological parameters of the brain. These are purely structural and have nothing to do with function.

Brain scans of by now thousands of people have conclusively shown that there are no male or female brains. With this people mean not the brain that is found inside a biological male or female but the brain of someone with feminine traits who is therefore a "typical woman" or masculine traits and "typical man".

In terms of brain scans it's impossible to take a scan of someone's brain and then have someone else determine with any accuracy greater than 50/50 if this is a man or a woman. That's because all these typically masculine and feminine traits are present to a lesser or greater degree in all of us. IOW for once this really is a spectrum and men and women are both found at either end and anywhere in between.

Regarding the research on transgender people's brains, it is incredibly useful to read the actual papers these claims are based on. Very often the conclusions are bold but not supported by the results. This is frequently then confirmed when follow-up studies find different results directly disproving those claims.

What has been found relatively consistently so far is a difference between the brains of homosexual transsexuals (early-onset transsexuals ie transkids) and that of non-trans heterosexual people. As most of these studies however did not include non-trans homosexual people, it's impossible to say whether the differences aren't grounded in the subjects' sexual orientation.

And as for the OP's question regarding hormones - for whatever reason, to prove that people are born trans is seen as the holy grail for trans activists. However, because of the rarity of transsexualism this is yet more nonsense and completely illogical.

GIRES (a trans org) estimates that 1 in 100 people in the UK are transgender, but only 1 in 14,000 males and 1 in 38,000 females is transsexual (in the sense that they suffer from severe and acute gender dysphoria that can only be alleviated by feminising/masculinising the body and living according to their idea of what it means to be a woman/man).

Say it was shown that transsexuals were indeed "born trans". According to the GIRES data, this would validate merely the claims of said transsexuals, ie 1.4% of transwomen and 0.7% of transmen

(If we assume an even 50/50 split between the sexes for simplicity's sake. In actual fact, the vast majority of people self-identifying as trans are men, which would decrease the % for transwomen and increase that for transmen).

The rest would still lay claim to the "born this way" myth but have no evidence to support it, hoping that people will simply accept these claims without question. This rarity of the condition among trans people may well be why transsexuals are called tru scum by activists. Bizarrely, it seems like they're almost seen as having a form of trans privilege for actually having gender dysphoria.

That's really interesting CharlieParley.

It's estimated that only 1% of people who say they are trans have a GRC. And talking to transsexuals, on here it generally seems to be something that they all obtain.

Presumably the extent of their dysphoria leads them to go to the maximum possible to become official 'women'.

Which is similar to GIRES figures. And would also correlate with Blanchard's categorisation of homosexual transsexuals, and autogynephiles.

Do GIRES acknowledge AGP? I must admit, I didn't think they did.

If a particular trait is found in both men and women, even if it’s more common in one than the other, some kind of logical jump is required to reach the conclusion that the trait doesn’t just occur in both, but is evidence that the men are women or vice versa.

@CharleyParley
Thanks for going through all this. I think it’s really important we get this straight. If those of us arguing for the preservation of sex as a protected characteristic – which seems to be what it boils down to – hold that transactivists are going against biological facts we need to be damn sure we have a clear grasp of what those facts are. Otherwise we can be made to look like the ones who are going against science as some TAs claim.

Yes, we agree there are differences between men’s and women’s brains in a similar way to there being differences between men’s and women’s heights. So, they are different, but you couldn’t differentiate between the two groups based on their brains. There is a recent massive study from the UK Biobank confirming this.

What has been found relatively consistently so far is a difference between the brains of homosexual transsexuals (early-onset transsexuals ie transkids) and that of non-trans heterosexual people. As most of these studies however did not include non-trans homosexual people, it's impossible to say whether the differences aren't grounded in the subjects' sexual orientation.

There has been a good recent Swedish study on this, which included both homosexual and heterosexual people as comparators for transexuals. They did identify changes in a specific brain region (inferior fronto-occipital fasciculus) linked to being transexual. Importantly, the transexual group all had a clear diagnosis of gender dysphoria. Swedish study

GIRES (a trans org) estimates that 1 in 100 people in the UK are transgender, but only 1 in 14,000 males and 1 in 38,000 females is transsexual (in the sense that they suffer from severe and acute gender dysphoria that can only be alleviated by feminising/masculinising the body and living according to their idea of what it means to be a woman/man). Say it was shown that transsexuals were indeed "born trans". According to the GIRES data, this would validate merely the claims of said transsexuals, ie 1.4% of transwomen and 0.7% of transmen

This is really important. The biological evidence relates to that small percentage of people diagnosed with gender dysphoria.

The rest would still lay claim to the "born this way" myth but have no evidence to support it, hoping that people will simply accept these claims without question. This rarity of the condition among trans people may well be why transsexuals are called tru scum by activists. Bizarrely, it seems like they're almost seen as having a form of trans privilege for actually having gender dysphoria.

So a bunch of people (trans activists) going around telling everyone they feel a bit trans and telling people with gender dysphoria they are scum. Nice. Imagine if this was happening for autism. A bunch of people going round telling everyone they feel a bit autistic, that laws should be changed to accommodate their feelings and calling people with an ASD diagnosis scum for pointing out that they don’t actually have the condition. Not a good idea to enshrine self-ID in law.

@flowersonthepiano

Thanks for that study! That was an interesting read. It confirmed that once normalised for sexual orientation a lot of the differences they found disappeared (ie no underlying factors for being trans). The one difference they did find mirrors the findings of another recent study which also showed that body perception and perception of oneself do indeed differ in people with gender dysphoria (which is congruent with the diagnosis after all).

What neither study shows is any evidence of people being born this way (all the subjects were 18 or older and according to the authors what they did measure changes with age) or an underlying condition that causes transsexualism. That's because the findings report on someone already diagnosed and may merely be a neural indicator of an existing condition (and not its cause).

And if self-id was indeed just for transsexuals (as the vast majority of people assume it is) I would have fewer objections, especially since they do tend to transition medically and safeguards could therefore be established that take this into account as evidence.

But the push to demedicalise and to sever any connection between being transgender and having a mental health condition actually harms transsexuals who need (and seek) both medical intervention and mental health treatment.

Oh and you're correct, as of the last official count there are indeed about 1% of the trans community with a GRC. The actual number is just under 5000 (stat from end of 2017).

@CharleyParley

That's because the findings report on someone already diagnosed and may merely be a neural indicator of an existing condition (and not its cause).

Of course - must remember correlation does not equal causation

Brain scans of by now thousands of people have conclusively shown that there are no male or female brains. With this people mean not the brain that is found inside a biological male or female but the brain of someone with feminine traits who is therefore a "typical woman" or masculine traits and "typical man".

I am sorry, I am writing and looking after DC at the same time, but is this not the crux of the matter - there ARE no innate masculine or feminine traits, because society may determine something is not feminine and then 100 years later, it is accepted as perfectly normal.

So, it was seen as 'unwomanly', therefore masculine, to be an educated professional woman in the late nineteenth century, and there were fears that women would become infertile and lose their looks from too much studying; whereas now, our laws and norms mean that half of all university graduates are female, and no-one is arguing that female graduates are 'manly' and therefore less fertile and less attractive. So, what is seen as masculine and feminine traits is fluid, not static.

So, on that level, to talk about a female and a male brain is meaningless, as it is dependent on how society views and values certain traits. I always understood gender to be the term used to describe these socially-constructed, and therefore malleable, challengeable and flexible in an individual.

Gender is separate, less well-defined. It refers to your own perception of your maleness or femaleness and whether this matches your physical sex, and is quite possibly a spectrum.

I think this is how gender has been re-defined by the trans lobby. This is not a definition that I have seen until relatively recently, and if you look at documents where trans groups have been on advisory boards or panels, the language around this is almost word for word the same. Gender as used in this way re-shaped the previous definition of something socially constructed and external, to an internal relationship with one's physically sexed body. It did not previously have that meaning.

So, my question would be when did gender change from being accepted as socially defined sex roles, to some nebulous and immeasurable concept inside one's brain?

Anyone who ever challenges the idea that being female means embodying the external, socially accepted ideas of femininity would struggle with this internal-brain definition of gender, to be honest, because what does 'feeling like a woman' actually mean? It can only be grounded on external appearances of being a woman, which may extend to physical embodiment and appearances of female humans (and that is all a non-female person can experience). Because the actual lived experience of being a woman can only be experienced by actual women, unless I am missing something, that is logical.

So, we are being asked to expand what being a woman means. Whereas, what is necessary is expanding the confines of masculinity and femininity (or doing away with such definitions of appearance and behaviour altogether), so that there is no such thing as a perceived 'female brain' in terms of perceived feminine traits, there is just the brain of an adult with certain personality traits and ways of being, in either a female or a male human body.

I don't know, I struggle as I really do not know how to use gender any more as a concept. I don't think it is helpful, because in society, it is used to mean sex, gender as a social construct and gender as this nebulous thing in your head - all of which have contradictory meanings and implications.

I don't know, I struggle as I really do not know how to use gender any more as a concept. I don't think it is helpful, because in society, it is used to mean sex, gender as a social construct and gender as this nebulous thing in your head - all of which have contradictory meanings and implications.

You are right. I keep going on about definitions and then failing to use them properly myself. I think the correct term is "gender identity"

there ARE no innate masculine or feminine traits, because society may determine something is not feminine and then 100 years later, it is accepted as perfectly normal.

I'm not sure I'd be as adamant as this. I'd say that many, probably most, traits are deemed masculine or feminine by society and change with societal norms. However, I think it likely that some behaivor traits are influenced by our physical sex, because of the influences of hormones on the brain. Don't have any good evidence for the latter, but haven't looked for it yet. I will, but must do some actual work at some point....

bold fail

He's using intersex conditions to explain dysphoria. That link has been repeatedly disproven to the point intersex activist groups have asked that people to stop doing that, as others said, due to how it has been used to support prenatal and at birth interventions that are not needed (like giving mothers hormones), among other things. Intersex people are no more likely to be dysphoric than anyone else. Even within the research on the hypothesis that some people may be predisposed to becoming dysphoric due to biological reasons (likely alongside social ones), doctors can - based on the DSD diagnosed - tell what the most likely gender identity of an intersex person just as with someone who is not intersex. That research has helped medical care for intersex people but the myths still hang around.

Intersex is for those with disorders of sexual development, not for the natural range of female/male bodies or certainly not for feminine / agender / masculine traits which is how he appears to be using it to me.

I don't understand how he can say that sex is a spectrum and then say "whether you develop a male or female brain" and how sexual dimorphism affects the whole body including the brain (while at least a third of human genes are sex-biased and react differently by sex, we don't typically say the lungs are female/male even with the very obvious average differences). Sexual dimorphism is a binary, calling it a bigger word doesn't change that. The dividing the brain like that goes quite against research both that others have mentioned that there is no feminine/masculine brain but also the research on gender identity which, at least that I've seen, that while we may have innate traits that society classifies as feminine/agender/masculine and that might lead to a self-perception which could lead to dysphoria, to put it down to female/male brain or prenatal hormones is simply not accurate. At best, the prenatal hormonal hypothesis is just that, one hypothesis that doesn't have strong evidence and even the evidence it does have is only really meant to try to explain some but by no means all dysphoric people. Really, the hormones idea has also been used as a science-sounding argument for a lot of things like sexuality and aggression and personality traits and the evidence for it really, that I've seen, shows it might be one minor factor out of many more important ones.

Brains, just like the bodies they're part of, are complicated but I think there is a current trend to make sex seems overly complicated in order to make their science-sounding-but-simple argument for gender identity seem more reasonable. We don't know why some people experience a gender identity, we don't know why some people who don't experience a gender identity have or at least clearly show dysphoric symptoms. There are lots of ideas but I would ignore anyone that says there is one explanation at this point.

There is a lot we don't know, but the typical physical attributes of female and male people and the social hierarchy based on that Debbie Hayton is talking about in the article is not one of them and the attempts by TRAs to act like we know so little about sex and know so much about gender identity is someone either messing with facts or been taught wrong. I've seen a lot of weird ways to dismiss sex (weirdest to me is probably that it's a colonialist/imperialist con, like before colonialism some societies didn't have sexism or know how babies were made...).

I've seen a lot of weird ways to dismiss sex (weirdest to me is probably that it's a colonialist/imperialist con, like before colonialism some societies didn't have sexism or know how babies were made...).

That's the one that always makes feel as though I'm living through the equivalent of the fall of Rome in Western society!

When you say behaviour traits influenced by hormones, flowers, do you have any examples in mind? And if they are hormonally influenced, that is biological, and based in the body?

I think I see what you are saying, so behavioural traits which are seen to be gender-specific (say, aggression and violence = masculine = usually male) - if this behaviour is linked to testosterone, say, then that is hormonal and therefore based in the lived, sexed body, does that mean men are therefore violent and aggressive or it is socially more acceptable for men to be violent because they are physically more powerful and stronger.

If one says that hormones influence behavioural traits, and therefore violence is hard-wired in male brains, along a spectrum, then how does that explain societies where men live in peace (are there any?) and does that mean women are screwed as men (as a class) are innately testerone driven, therefore violent.

To me, biological essentialism, which this argument is, is just as dangerous as saying sex does not exist. But I think you may well be right that nature/nurture falls somewhere between both.

If we accept that there are numerous ways to define sex, let's compare non-transgender males to transgender males, using these criteria (as listed in the cnrs article linked by mirialis):

gametes of typical non-transgender males = spermatozoa (i.e. male)
gametes of typical transgender males = spermatozoa (i.e. male)

genetic sex of typical non-transgender males = XY (i.e. male)
genetic sex of typical transgender males = XY (i.e. male)

anatomical sex of typical non-transgender males = functioning penis and testes (i.e. male)
anatomical sex of typical transgender males = functioning penis and testes (i.e. male)

"hormonal gender" of typical non-transgender males = predominantly male hormones (i.e. male)
"hormonal gender" of typical transgender males = predominantly male hormones (i.e. male)

I think men like to imagine that there are brain differences so that they can feel superior and the alternative is unacceptable ie that women are just as capable as men of rational thought and critical thinking and that we see through them and find them sorely lacking in most departments.

Trans women don’t have a female brain because it doesn’t exist. The truth is far more mundane. We’re all just human beings. What they’re seeking isn’t real which is why they get so cross about it. They’re chasing a fantasy.

I really insightful thread, thank you.

I think where this becomes difficult is when people try to ignore, suffocate, twist, gaslight, use double think and 'science' to 'prove' they are something they aren't. And then tell you (women) you're the wrong one for not agreeing and a bigot etc etc etc.

The use of 'bad science' to prove a 'feeling' (and sound knowledgeable and authoritative) is quite chilling.

Many trans people are very honest and accepting of their biology; it's part of who they are.

I don't give a monkeys how people dress or live their lives. I do appreciate how hard it is for them actually, and it's similar oppressions to those that women find them selves under. I do object to brain washing and gaslighting using science.

These things don't affect my personal daily life but I can see how they affect others. I can also see how these narratives enter society's subconscious and consciousness and do have direct impact on young and vulnerable people and children (I've seen it) and that's really not ok.

It's interesting though that I would say that I feel some degree of gender dysphoria - not in relation to my body feeling wrong but in relation to my gender identity - I am not feminine and often feel out of place in a group of women, e.g. because I don't "dress up" on a night out (to give a shallow example). However, I'm quite clear that it's society that's at fault and not my biology or psychology - I guess feminism helped me with that and I was going to say that maybe men don't really have that theoretical body of work that they'd identify with in the same way to help to put it into context - but that doesn't explain why there are now more girls wanting to trans than boys.

I think there very likely that epigentics play some sort of role in some cases of all sorts of "divergence from the norm" (e.g. gender and body dysphoria, Aspergers, homosexuality, intersex).

As people have said so many times on here, when someone is anorexic we don't say "yes, you're right, you are fat" etc.

But also, with things that are not harmful (like anorexia) but are different from "the norm" (e.g. non NT thinking or homosexuality), society has needed to increase understanding and adjust to realise "this is not wrong, has pros and cons like so many other things and the more diversity we recognise and seek to understand, the more we learn and progress" but we don't pretend that homosexuality is just the same as heterosexuality, we don't pretend that there isn't such a thing as broadly NT thinking, and we don't pretend that intersex conditions are to be considered as "on the same level" [to quote the researcher] as being male and female like 98% of the human species. And in that article I'm referring to:

The desire to lump human beings categorically into two sexes at all costs has led to the constant recourse to weighty hormonal and surgical therapy from infancy onwards in order to ″correct″ subjects who are viewed as ‘neither one thing or another’ or ‘a bit of this and a bit of that,’ despite the criticisms levelled by certain intersex adults and some doctors against the policy of the scalpel that is synonymous with irreversible changes and physical and mental suffering. Although necessary where there is a risk, for example of gonad malformation degenerating into a cancerous tumor, “sexual re-assignation surgery for conditions that are not life-threatening results in physical mutilation in the name of the biologically questionable principle of strict duality,” concludes Pascale Molinier. “As always, the road to hell is paved with good intentions.”

Trans people shouldn't need hormones and surgery to force themselves into some sort of strict duality unless this is something they feel they must do at all costs. They are just as human and just as valid as the rest of us who are gay, non-NT, disabled (and here I really object to their frequent reference to "black women" as divergence from "the norm"!) and do need "consideration" (as Redhood put it) for having a particular set of needs that not everyone else has, but the solution to that is not pretending that being a transwoman is just the same as being a woman, nor that there are areas where the needs of women, men, transwomen, and transmen each diverge from one another.

I'm not sure why TRAs/trans lobby overshot the mark so quickly with this? Perhaps due to the long fight for gay rights, they've decided on "Go hard or go home"... but society was so prepped to be "on the right side of history" with this, we've now found ourselves in the ludicrous situation where people are earnestly chanting that transwomen are women and proudly flying their flags as "trans allies".

Funny how disability access and rights never became the cause célèbre.

@katara

If one says that hormones influence behavioural traits, and therefore violence is hard-wired in male brains, along a spectrum, then how does that explain societies where men live in peace (are there any?) and does that mean women are screwed as men (as a class) are innately testerone driven, therefore violent.

To me, biological essentialism, which this argument is, is just as dangerous as saying sex does not exist. But I think you may well be right that nature/nurture falls somewhere between both.
Yes, that’s exactly the sort of thing I was thinking about. The link between aggression and testosterone levels is not completely clear. I found this interesting paper (testosterone paper) that seems to be well designed (double-blind control trial), showing a link between testosterone and dominance behaviours, including punishment and, surprisingly, also generosity. These are described in the paper as behaviours involved in achieving and maintaining higher social status. So there may be hope for us yet.

@mirialis

YY agree that epigenetic modifications are good candidates for these sort of variations. Is there any evidence do you know?
Could not agree more with all the rest of your post, particularly

Trans people shouldn't need hormones and surgery to force themselves into some sort of strict duality unless this is something they feel they must do at all costs. They are just as human and just as valid as the rest of us who are gay, non-NT, disabled (and here I really object to their frequent reference to "black women" as divergence from "the norm"!) and do need "consideration" (as Redhood put it) for having a particular set of needs that not everyone else has, but the solution to that is not pretending that being a transwoman is just the same as being a woman, nor that there are areas where the needs of women, men, transwomen, and transmen each diverge from one another.

I am also increasingly beginning to wonder how much of the increase in self-declared trans status among people not diagnosed with gender dysphoria is an extreme form of the apparent increase in acceptance of surgical changes to healthy bodies to make them more conventionally attractive (boob jobs etc.) It doesn’t seem that unusual a choice these days to have implants or other invasive procedures in an attempt to improve your self-image, regardless of whether you are trans or not.

flowers - there are lots of studies about epigentics focused on specific areas. One thing - among others - I'm vary wary of is the fact that the focus is 'in utero' can make some hypotheses and assumptions yet another stick to beat women with; moreover, I don't think we can ever get "behind the curtain" of post natal environment to truly remove it from the picture. I do think that it is likely that there are some general differences between populations (not individuals) that would suggest that sex differences are not 100% down to socialisation but I'm sure that's not particularly controversial even for rad fems and that it lends absolutely no justification to making assumptions about individuals based on their sex.

But, for example, I saw a very brief discussion of something quite recently (perhaps on twitter? - I don't tweet or have followers but do look at it to keep abreast of what the chat is there) about a study examining identical twins (as far as they were aware after analysis - but no DNA tests done - these were MZ twins), where one is gay and one is straight and they asked naive participants to assess as many childhood photos as they could provide and found from a primary, pre-pubescent age that naive participants were identifying the GNC twin (v straight twins and gay twins). I can already just off the top of my head think of two or three questions and limitations I could pose here, but it is interesting that these are genetically identical children being raised in as close to an identical environment as you can get, and that the possible difference between the two was something that occurred in utero.

In the past, what happened to these GNC kids? For a long time life was extremely difficult, ditto non-NT kids, and it's not to say by any stretch that life is still not very difficult for these kids and their parents and siblings and that we still have so much learning to do and progress to make but surely what we have learnt is that intrusive psychoanalysis, lobotomies, medication, behavioural therapy, castration etc. are exactly NOT what we should be thinking about let alone doing , nor denying scientific reality (e.g. heterosexuality is both "the norm" and essential for survival of the species etc.).

It feels so bizarre that now such large - and again I do appreciate it's not all - sections of "western" and/or "anglophone" society are finally in a place to get on board and celebrate GNC and other divergence that we would be urging anyone to take hormones/have surgery to fit a mould whilst simulatneously telling us that any attempt to define the boundaries of said mould is "colonialism" or "essentialism" or whatever.

But I think your last point also raises the question of whether someone's trans status is down to dysphoria (with a range of potential triggers including epigentics) and how much is about idolatory of the the Kim Kardashians of this world, the rise and hijakcing of "causes" like "feminism", "gay rights", "black lives matter" (ultimate cause for white "feminist" and "trans" or "non-binary" students to latch onto) and generally a lot of angst and navel-gazing and wanting to one-click order an idealised identity online that really doesn't translate down to genuine and debilitating gender dysphoria....