It’s very obvious all mammals are dual sex, no more no less. It’s a fact that there are only 2 sexes when it comes to mammals. They also have average behavior differences due to hormones and their structure, but this only goes so deep. Bulls for instance are more aggressive than cows on average - this is because their hormonal differences that stem all the way back to their chromosomal differences, but also due to their body differences (like extra muscle and size) that give them the ability and perception by other cows.
These things are the same in humans: we have our “run-time sexual differences” that come from hormones, and our “static sexual differences” from how those hormones have built our bodies over time. Men behave differently on average because of the hormones profile in their body is different from that of women. Men also behave differently because those hormones over their life time have changed their body to be larger on average, and this on another level has led them to have different experiences than women that have shaped their mindset and behavior (eg being larger means people treat you differently, and that reinforces different behaviors).
All this to say that the differences between the sexes are almost entirely immutably biological at the base (including the social construct aspects). The differences between men and women start from the chromosomes, and that decides hormones and body structure, and those two affect how people treat you naturally (a larger, more aggressive organism is treated differently than a smaller, less aggressive person), which creates over time what we call gender roles.
Some examples: men being deemed “protectors” isn’t just some arbitrary gender role out of the blue, it stems from the fact that one sex of the human species is obviously larger, and so naturally expected to step up in these situations throughout their life. Aka: if you reset everyone’s memory of gender roles, they’d likely come back and be pretty similar in broad strokes very quickly, because they are determined at the base by chromosomes > hormones > body structure > how others perceive you and the experiences you have in your life as a result.
Men can never be women and vice versa. You can change the hormones, but you can’t change the body structure, the chromosomes, the experiences of the individual and others, and consequently how others naturally react to them. Those aspects all together are what makes a man fundamentally different from a woman.
And: you keep saying "on average" without acknowledging what that implies: there is a distribution, and that distribution overlaps. Some women are stronger than some men; that doesn't make them men. Some women are more aggressive than some men; that doesn't make them men. Some women are larger than some men; that doesn't make them men. All of that means that you can't simply define man/woman on the basis of size, strength, or aggression.
Looping back to gender: it's a social construct, and there is no way for a non-human mammal to declare what they think or feel in a way we can understand or interpret. (Lack of) examples from the animal kingdom have no bearing.
My point is that sex deeply influences gender. Gender expression and gender roles have a direct line to sex via chromosomes > hormones + body structure > how you behave and how you're treated.
You can of course call yourself whatever you want, but expecting others to adhere to that, or even being bothered that they don't, is senseless.
So when a man calls himself a woman, and says it's on the basis of some internal feeling of being a woman - how on earth is he supposed to know what that is like? Being male, he has absolutely zero reference point for what it's like to be female.
He might desire to be a woman (and claim to have a "female gender identity" because of this), but that's not the same thing as actually being a woman. And if you look on the trans forums where these males discuss this, you can see it's all about performing stereotypes of femininity. Often related to being sexually aroused by the thought of cross-dressing - the so-called "euphoria boner", as they put it.
Furthermore, most of these men use their claims of having a "female gender identity" to demand access to women-only spaces, disregarding and violating women's boundaries, and defeating the whole point of why we have sex-segregated spaces in the first place. Gender identity is a dangerous, misogynistic concept that is harming women and children.
Thanks! Your saying "Being male, he has absolutely zero reference point for what it's like to be female" made me think.
That said, I disagree :-)
I'm male -- both in chromosomes and in thought -- but I know that (generally) being a woman involves wearing skirts, makeup, and in general softer, more elaborate clothes; paying more attention to grooming a certain way; maybe wearing makeup, at least a little; being deferred to in lesser matters like who goes first through a door, but expected to defer in more serious matters like where to go and how to get there. I don't have to experience any of the above to envision what they feel like, or to know whether I would be more comfortable experiencing them one way or the other.
Calling these things "stereotypes" is a silly minification of them. If they are just stereotypes, then women should be able to discard them whenever they wish, but that is far from the case when it comes to negotiating, advancing, getting their way, etc., etc.
"And if you look on the trans forums where these males discuss this, you can see it's all about performing stereotypes of femininity." You've done extensive research? :-) And again, "stereotypes" is dismissive.
Your last paragraph is an unjustified panic, but I'll at least reply to say that if I were to be concerned about someone in the bathroom, it would be concern for someone who presents as a woman, but is forced to use the men's room because beneath their poodle skirt they happen to have a penis.
Men and women have different chromosomes. They have different skeletal structures. They have different amounts of hormones. They have different averages.
Women can have children. Men cannot.
The fact that people are trying to argue otherwise is frankly insane.
Saying men and women have different chromosomes is circular logic. You're saying that XX = woman and XY = man, and then defining "man" and "woman" in terms of the standard you set up for them.
As I responded to in a different reply, skeletal structures exist on a distribution. Those distributions generally overlap, meaning there are some women closer to the "male" average, and some men closer to the "female average. That doesn't determine their gender or even their sex.
Edit to add: you list hormones as a determining factor -- but hormones can be adjusted. Would you agree that a person who achieves "male" hormones through pills or injections qualifies as male? Or vice versa?
Saying they have different averages ignores that distribution, and again would arbitrarily classify some people as the opposite of their chromosomal classification.
"Women can have children" -- even among XX women, that's clearly false. Or are you saying that women who can't bear children aren't women?
Your use of the word gender is effectively "personality". Yes people have different personalities.
Yes XX is a woman and YY is a man. Mammals require one of each to reproduce. Creating a clear, simple definition is what science is supposed to do so that we can better understand existence.
When a woman can no longer have kids she has gone through menopause or had a genetic aberration that prevented her from doing so.
Yes there are bell curves within nature. This doesn't change chromosomes.
No I would not agree that hormones received from an external source make one male or female. If I color my skin green, my skin is still not green. I have simply made it appear that way.
Personality is an element of gender, but they are not synonymous. Even in your definition of men vs. women, there are people of all "personalities" in each "gender".
Yes, science classes chromosomes, and yes, one of each is (generally, let's not get too caught up in parthenogenesis) required to reproduce. Is that all you see in men v. women? You used reproduction as a determinant, but now you're saying that women who can't reproduce are still women because...they're supposed to be able to reproduce? That's not quite circular logic, but it's darn close.
Taking hormones is pretty far from "coloring your skin green" -- by your definition Arnold Schwarzenegger wasn't really as muscular as he was, or Lance Armstrong as fast as he was, because they took steroids/PEDs. It's easy to argue that they cheated, but hard to argue that they actually weren't as big/fast as they were.
Your argument seems to simplify to chromosomes. Of course you know that there are people born with neither XX nor XY. You can claim those people are "something else," but if they want to present as male or female, is that wrong? And I'll ask you the same question I posted in a separate comment: if we were standing in Times Square and I asked you to point out the women walking by, would you really say, "I can't until I get blood samples"?
And to your point, the things an XX chromosome does lead to can be changed, with hormones, etc.