I'm trying to determine the inflection point where femaleness is defined. It's clearly extremely important to posters on this thread! This seems like it lies at the very core of the issue being discussed here - how do we define femaleness? Is it genetic? Primary sex characteristics? Socialisation? The combination of all three?
The female sex in humans is characterised by XX-chromosomes, ovaries, fallopian tubes, uterus, vagina internally and a vulva externally, with breasts normally developing in puberty. There's no inflection point (the point in a curve after which it changes direction) for femaleness because when you plot males and females in humans, you're not plotting curves but separate bar graphs with a whole universe of nothing in between.
Might I recommend Peachyoghurt's excellent video here, since you seem to believe that a member of the female sex not being equipped with all of those things somehow invalidates the whole category and qualifies males to enter it:
You say the matter is complex - I agree! It's extremely complex! I'm trying to find a workable definition we can use in discussion.
We have a workable definition, thank you. How about you apply that female socialisation you say you cultivated for yourself and accept the definition we're using, which is the biological definition of woman, as used in UK law?
Which is: a woman is an adult human female. Female denotes the sex capable of producing ova and bearing offspring. (I described the equipment that this typically includes above.)
You have sadly misunderstood the points we were making about socialisation completely. So to be clear: socialisation does not have a bearing on an individual's sex but only on their personality, as expressed in preferences, dislikes, behaviour, mannerisms and so on. Socialisation does not determine sex. That's because sex is determined at conception and observed at birth. Socialisation only starts after birth.
A thought experiment:
Take twin children, a boy and a girl, and subject them to opposite-sex socialisation. In puberty, which of the two will you talk to about the possibility of falling pregnant when having sex?
Obviously, we both know the answer to that.
Our point about socialisation is not that it determines the sex of female individuals but that it determines our behaviour to such an extent that it is extremely difficult for male people to successfully pass as female when they interact with female people in real life. Female socialisation comes with a lot of attributes that male socialisation does not. It is hard to unpick and even harder to convincingly mimic precisely because it requires us to do so many things to fit in that male children are simply not expected to do. To use your words, our minds are encoded from birth with self-negating attitudes and behaviours that boys' minds are not. That's why many male transgender people give themselves away as male even when their outward appearance does not obviously do so.
Like the prettily dressed male who pushes past the queue in the women's toilet, or the male panel member on an otherwise female panel on women's issues who dominates every time despite having little real understanding of the issue. (The latter for instance hammered home sex in a way that appearance didn't for an audience who mostly didn't know the speaker was trans.)
It's often a combination of complete or partial ignorance of women's experiences growing up female in a male-dominated world who now as adults still navigate the same issues coupled with male entitlement which manifests as that unshakeable belief that what men say is worth listening to, that they have a right to speak and a right to be listened to, that what men do is worth doing, that they have a right to do it and a right to keep on doing it, regardless of what women think. And so on.
And I'm not saying your behaviour on here proves you cannot successfully pass in real life. I don't know you, and we're having a debate where we're on opposing sides that wouldn't be happening if you didn't feel in some way that you were right and wanted to find agreement that this is the case. That alone tells me very little about your actual behaviour in real life.
The one thing that raises doubts in my mind though is that you are not clear here - are we having this debate because you wish to carve out an exception for male transsexuals who have fully transitioned, or only for those who are fully or partially puberty-blocked and fully transitioned or for all who sincerely believe themselves to be female, who may or may not be able to transition? I mean who are you arguing for and to what purpose?
As for 46, XY - you know better than that ButterflyHatched. People with DSDs are not a gotcha to use in this debate. That's for teenagers (like mine when they think they're being clever. It doesn't work for them either).
Furthermore, 46, XY covers about 17 or so different conditions, which result in children born with clearly male, clearly female or ambiguous genitalia. When the latter happens today, the child and its parents are referred to specialist doctors who investigate what condition the child has, how it may develop and what specific healthcare needs he or she will have throughout life.
An 46, XY child born with female genitalia is obviously female-bodied and will therefore be registered and raised as female. If you remember that chromosomes are merely the starting point of sex differentiation and not the end point this will make much more sense to you.
The starting point are XX and XY chromosomes. If everything goes right, the end point is a female-bodied child or a male-bodied child respectively. If something goes wrong along the developmental pathway, the end point may be a male-bodied child and a female-bodied child respectively. And this is how these children will be classified. Their personal circumstances do not change the sex categories in humans though.
Which is why none of that has any bearing on the sex of male adults who wish to be female. Or validates the claims of those born as phenotypically completely unambiguous XY males to have changed sex.
Take polydactyly. It happens in 1 in 500 live births. (Ambiguous genitalia are observed in around 1 in 5000 live births. 46, XY females are estimated to occur at a rate of 6.4 in 100,000 live births.)
The fact that 1 in 500 children are born with more than ten fingers and/or more than ten toes does not invalidate the fact that humans come with ten fingers and ten toes as standard. The human blueprint doesn't change just because there's been an error in production. It stays the same.
This is also true if we look at people born with DSDs. Yes, their bodies differ from the human blueprint. No, that doesn't mean the blueprint is no longer valid. Because the blueprint is valid for 99.98% of us. Given that the human blueprint including ten fingers and toes is only valid for 99.8% of us and we're still not throwing it out as valid for fingers and toes, we're most definitely not going to throw it out for the sexes.
HTH