The liminality of sex perception, sex-based spaces and bodily autonomy.

[polypostwonder]

This thread continues a discussion between BonfireLady (sorry, I wanted to tag you but the system says your username doesn't currently exist) and I on biological sex vs perceived/observed sex in https://www.mumsnet.com/talk/womensrights/5530455-us-to-open-worlds-first-childrens-detransition-clinic-texas-hospital-to-offer-free-services-reversing-the-effects-of-gender-affirming-treatments?page=10&reply=152406258

She has requested I answer the following two questions:

1. would you consider that a viable way forward is for you to self-exclude from women's spaces and instead either advocate for third spaces for anyone to use (e.g. unisex facilities in addition to single-sex) or (probably your least preferred) use the men's?
2. would you support a restriction on anyone under 18 (or 25?) making permanent changes to their body, to match it with their perception of their "gender"? Similar to other restrictions on permanent body changes.

I believe I have previously answered them both. My answers today are superficially the same, but I have better thought out my answers (maybe?). To do this though, I need to share some assumptions.

In the previous thread, I believe there was somewhat of an agreement on the following statements:

1. People can identify a man when dressed in clothes 'traditionally associated' with women. Clothes are superficial to sex.
2. People look at other people and perceive their sex. People are not identifying the gametes/sry/chromosomes/other unobservable immutable biologic factor inside another person.
3. Assumptions about sex are made based on a person’s sex characteristics amongst other observable cues.
4. Pretty much every person in the whole world "exists within the expectations of sex categories". Very rarely it's unclear.
5. If a person exists within the expectations of sex categories, then socially they are treated as that sex whether they wish to be or not.

Building on those statements and previous discussion, some additional thoughts:

1. ‘Biological sex’ is defined by a person’s gametes/chromosomes/sry/other unobservable immutable biologic factor. This cannot be changed.
2. ’Observable sex’ is based upon the perception of sex characteristics rather than known biological sex and influences the placement and treatment of people in social sex categories. Perception is not under control of the observed, nor is it a demand of others.
3. Observable sex can be heavily influenced by biological sex and sex-based function. But sex-based function is not a requirement for the perception of sex.
4. Women’s rights are a cultural accommodation to rebalance access to society and ensure health, fair treatment, safety and/or dignity. Not all women require or access every right, but these rights are a vital benefit to women as a class.
5. Users of a culturally defined space for members of one sex may feel comfort, privacy or protection through separation from non-users. But all users share an equal right to feel comfort, privacy or protection.
6. Misogyny is not biologically based. It is a prejudice directed at women’s observable sex. Sexism can be biologically directed, but it can also be directed at members of an observable sex.
7. Sex realists believe every person should live and be treated by society according to their biological sex, no exceptions.
8. Trans people have a wide range of beliefs and goals. They do not share a single motivation.
9. Better quality research should be done with trans people of all ages.

I think BonfireLady is correct in saying each of us sees the other's "belief" as non-sensical and our own as position as factual. I'm hoping we can discuss this from a somewhat sensical space.

Quite so. Blethering on about his paperwork clearly shows he isn't a woman as no woman needs a piece of paper to prove it.

Imagine thinking you are justified in claiming any provision for a female person when you are a male.

No male people should be on female shortlists. It doesn’t matter whether as a male person, that person was not getting on shortlists or opportunities, male people have had advantages from birth collectively that female people have not had access too. Female shortlists are there for female people, not male people who wish to claim a place on that list.

I am thinking that these posts are wind ups now.

The long term ‘room sharing’ with a female person who didn’t know they were sharing with a male person, the unshamed claiming of female shortlist positions and no one could tell they gave that position on the shortlist to a male person. There is something very disconnected in these.

@Helleofabore the response, if any, will be that the poster did not actually claim any female provision or place, they just happened to be included in it by others and...hey... just went along with it...what can you do? etc.

They observed and treated me as a woman, so instead of simply speaking up and saying "no, actually..." I just took women's stuff

It's so solipsistic, isn't it.

yes. While at the same time denying that they did it.

Goah! It is like we have been on rinse and repeat now for months.

The GRA superseded Bellinger v Bellinger. I read the references and located the 'indicia' paragraph. The context around the paragraph in Bellinger v Bellinger does not identify relevance to the factors as you do. I would surmise they are contextually equal and contemporaneous; in preparation for a trial for example.

If I query the factors as they apply to me, and as they have applied for my adulthood:

1. My sex chromosomes are XY, tested when I was a child
2. Gonads, do not exist
3. Internal structures, do not exist
4. External structures, surgically created vulva, clitoris, etc.
5. Hormonal patterns & secondary sex characteristics: female
6. Upbringing & living: queer boy > trans girl > woman
7. Self-perception: female

I cannot prove that 1-4 were in any specific form at birth. I cannot prove I would have developed as a typical man had I not transitioned.

I would object to an observably male non-trans 6'4 rugby player. For the sake of conversation, I am assuming they are an absolute unit because I believe that is your intent.

My concern would probably decrease somewhat if evidence presented of a transition attempt. It would probably also depend on the location of the loo. I recognise other women do not feel similarly.

My brother is over 6' and played rugby in school and uni. I surprisingly, did not.

I have several passports, a driving license and a birth certificate ('original,' certified long-form from the early 90s). I can't remember the last time my 'birth sex' was explicitly required for something.

Historically, and across many cultures there's an understanding that 'sex and gender' (in the interest of saving words, I don't like it either but it's early and I have to get out of here...) were related (closely in most people) but different contexts. In English, we have 'woman' for social sex/gender and 'female' for sex/physical. The separation grew looser and remained okay for women as long as it served women. No one was confused when someone said 'woman' or 'man' or 'male' or 'female.' Feminism was instrumental in building distinctions and between the two to identify structural imbalances and power dynamics as applied to gender/sex.

Gender critical people have been recombining the two, to the point of manufacturing this crisis. It's found some legal legs, because of some well-connected gender critical people, financed by American culture war organisations and cemented by socially conservative judges. (yes, admittedly somewhat of a conspiracy theory).

I know sex change is possible, because I have lived it. I don't know how many people experience it. I know the likelihood was increasing as the age of treatment lowered to the age I began, then dropped even lower.

I also recognise the reality that many do not change to the desire they wish or to a place is considered 'enough' for some non-trans people who share space with trans people.

I believe 'woman' and 'man' are socially acceptable words to include some trans people because they (speaking of medically transitioning people) are altering sex characteristics. In some people, this can also mean developing the sex characteristics opposite to their birth sex in puberty, such as I did (or earlier!). They are socially identified as men and women. Regardless, many visually trans people are also integrated as 'men' and 'women' by families, friendship, policy and law (dependant upon where/when/why in the UK).

I believe trans people who are non-transitioning, or those only social transitioning are difficult to place culturally. Outside of personal relationships, the law and policy mostly followed trans accommodation, but I think the legal situation in the UK is demonstrating the difficulty in sustaining the link.

I still believe most people—most women—just don't care about this topic as much as people engaged in gender critical debates. If presented with a question, most people are prepared to answer in a poll. This doesn't reflect any deep thought or reasoning. 'Men in a women's loo' will always be viscerally wrong.

Women ultimately decide on who is a woman. No one is forcing you to be friends with trans people.

I quoted Bellinger v Bellinger because the newly published EHRC Code of Practice refers to the factors listed in the section of Bellinger that I quoted. It's paragraph 2.88 of the Code of Practice. I'll quote it again.

2.88 The Supreme Court in For Women Scotland ruled that ‘sex’, ‘woman’ and ‘man’ in the Act mean biological sex, biological woman and biological man. The judgment uses the expression ‘biological sex’ to describe the sex of a person at birth. Earlier case law [footnote 12] has set out the indicators of biological sex.

Equality Act 2010: Draft Code of Practice for services, public functions and associations, 2026 - GOV.UK

Footnote 12 - Read, for example, Bellinger v Bellinger [2003] UKHL 21 at paragraph 5

The newly released Code also says
2.49 The Supreme Court in For Women Scotland Ltd v The Scottish Ministers (For Women Scotland) [2025] UKSC 16 has ruled that a GRC does not change a person’s legal sex for the purposes of the Equality Act 2010. The judgment held that ‘sex’, ‘woman’ and ‘man’ mean, respectively, biological sex, biological woman and biological man for the purposes of the Equality Act. The judgment uses the expression ‘biological sex’ to describe the sex of a person at birth. The phrase ‘biological sex’ has the same meaning when used throughout this Code.

-----

I'm not using it for the holding in the case but for the definition of sex since that was the definition used by the EHRC in the guidance issued on 21 May 2026.

---

The Supreme Court ruled that 'sex' and 'women' under the Equality Act mean biological sex at birth.

A person who is a biological man, ie who was at birth of the male sex, but who has the protected characteristic of gender reassignment is described as a “trans woman”. Similarly, a person who is a biological woman, ie who was at birth of the female sex, but who has the protected characteristic of gender reassignment is described as a “trans man”. We describe trans women and trans men who have obtained a gender recognition certificate (“GRC”) under the GRA 2004 as “trans women with a GRC” and “trans men with a GRC” respectively and their gender resulting from the GRC as their “acquired gender” or “acquired sex”.

We also use the expression “biological sex” which is used widely, including in the judgments of the Court of Session, to describe the sex of a person at birth, and we use the expression “certificated sex” to describe the sex attained by the acquisition of a GRC.

. . . .

The interpretation of the EA 2010 (ie the biological sex reading), which we conclude is the only correct one, does not cause disadvantage to trans people, with or without a GRC. In the light of case law interpreting the relevant provisions, they would be able to invoke the provisions on direct discrimination and harassment, and indirect discrimination. A certificated sex reading is not required to give them those protections (paras 248-263). (xviii) We therefore conclude that the provisions of the EA 2010 which we have discussed are provisions to which section 9(3) of the GRA 2004 applies. The meaning of the terms “sex”, “man” and “woman” in the EA 2010 is biological and not certificated sex. Any other interpretation would render the EA 2010 incoherent and impracticable to operate (para 264).

For Women Scotland Ltd (Appellant) v The Scottish Ministers (Respondent)

How can events that happened later in life be ‘present at birth’? Only things that were present at your birth could possibly be relevant to determining your sex at birth, which is what biological sex means in the Equality Act.

You're XY.

You say
Gonads, do not exist
Internal structures, do not exist

If you didn't have gonads or internal structures at birth, it sounds like you're a man. There was nothing present at your birth to indicate you were female.

Therefore, under the Equality Act, you are legally a man and have been a male since birth. Unless the law is changed, you'll always be a man. None of your arguments or certificates matter because they don't change your biological sex at birth.

I don't see any good faith argument that you're a woman in the UK.

You're probably legally a woman in Canada. If being a woman is important to you, why don't you move there? I'm genuinely puzzled.

Bin case you missed it @polypostwonder , if woman is now the word for a male, what is the word for an adult human female? It can’t obviously be woman can it as men have now claimed that word.

I meant trans, there is no argument about the male who knows he's a man.

Paralympics.

There is also elite level sport for old people these days.

And darts and shooting are sex segregated.

Now we know your history, PPW, I don't think you are actually in any position to advocate for people who went through puberty to be accepted into female spaces. You are nothing like them. You can't speak for them, you have no idea how they feel. Except for the male tackle, it sounds as if you were as close to female at birth as you can get without being female.

I'm really pleased for you that you found a role presenting as a woman. I'm really pleased for you that you were completely accepted as a woman.

But I'm actually now annoyed that you advocate for people who grew up with normal levels of testosterone and normal male physiology to be in women only spaces and on women only shortlists.

It's quite simple, you aren't representative of the majority of men who profess to believe that they are women.

PS I note your continuing evasion of discussing the AGF issue.

Internal structures, do not exist

Your prostate exists, even if "pickled".

1. *Gonads, do not exist
2. Internal structures, do not exist*

Does that mean you never had them, or that you’re saying they’ve gone due to the physical changes you’ve had made to your body?

Earlier on in this thread you said that:

Then my participation ends as my viewpoint is invalid within no shared reality.

For a little while it seemed like you might not come back, but you did. And, as I said before, I'm glad that you did.

I've found your posts since then interesting but this one particularly so.

Given it's very clear that you're not shifting your position on your belief that you are a woman** (TBF I didn't expect you to, and that's fair enough), and we've still got half a thread of space left.... how about expanding upon this? It would be a different angle to explore, now that we've hit the inevitable roadblock of "I say I'm a woman" and lots of MN posters say you're not.

**I'm afraid I don't believe you that there is no record of you being born male in the UK. Unless of course you weren't born in the UK and your birth country allowed self-ID from birth (like Germany does now). Although I do accept that you could have obtained a long-form birth certificate with your new "gender" (including after getting paperwork done abroad), if you were born in the UK, your registry office record will always still state your birth sex. That never gets changed, even with a GRC. It's just the certificate that does. Happy to be proved wrong and apologise if I have misunderstood the law in the UK on this.

It's not about being 'friends'. It's about protections in law.

Nobody gives a hoot what a man chooses to wear or call himself.

But he cannot and should not exploit the rights that women gained to enable us to have a more equitable place in society. Its unfair, its wrong, and it is illegal.

And yet, that doesn’t change the material reality that you are male and not female.

All my identification in the UK are in one name. That doesn’t mean that I never existed with a different surname in the past.

I don’t believe also that any country removes the birth record trail for anyone who changes the birth certificate they hold personally. That birth record still will show someone accurately recorded as being male.

It would be dishonest and unethical for someone to take a role requiring an enhanced DBS in the UK, without disclosing all previous names so that a full check can be done in all countries they have lived in as I have had done recently.

You have not had a sex change.

You are just assigning a different meaning to the word ‘sex’.

That is fine as long as you don’t expect anyone else to understand your definition and you comply with the law.

The births of most animals are not registered at all. Doesn’t mean their sex is changeable.

If a man could truly turn himself into a woman, and a woman into a man, we wouldn't be having the conversations we do

Agree, and the conversations would have nothing to do with identity.

They would be along the lines of “we’ve agreed that I’ll take time off to have the first baby, then we’ll switch and I’m going to win the men’s 100m”

@polypostwonder

It sounds as if you were a normal boy baby who had an early gonadectomy, exogenous œstrogen treatment, and vaginoplasty. You probably do pass. But gender recognition cannot be made conditional on such aggressive and unethical treatment (Garçon & Nicot v France) and it's likely to be illegal here for minors in the absence of a DSD.

Bellinger v Bellinger has not been superceded. Sex in UK law is determined by attributes present at birth – karyotype, gonads, and internal and external genitals (unless there's a relevant DSD making these four things unaligned). Practically, it can be found out by consulting the original birth registration, including any subsequent error corrections, which have retroactive effect. The Gender Recognition Register is additional.

If you want to be considered for a shortlist, prize, college place, fellowship, job, women's service, or women's club, it would not be illegal (and will sometimes be necessary) to demand proof of your sex and turn you away if you can't provide it.

A UK birth certificate issued before the age of eighteen would be proof.

Thank you for answering our questions.

OP says he has a surgically created vulva and clitoris, so they will have been fashioned from penis and testicles. Presence of those means that OP must have had functioning testes at birth.