What makes a man a man or a woman a woman?

[FreethinkingSceptic]

Does gender need anything more than one's own subjective judgement?

It does if it refers to anything objectively. I could say, in my own subjective judgment, that I am sexy, but other people are free to disagree.

I mean, gender is a social-laden term. It exists to describe something that exists solely in a social context, no?

When people identify with a gender that is the opposite of their biological sex, there are reasons for doing it, such as them feeling that, mentally, they are the opposite sex.

[FreethinkingSceptic]

Because gender is ambiguous. A man from Saudi Arabia and a man from the United Kingdom are different enough in dress and behavior, that if both were produced by the same culture they would likely be considered different genders.

No, a man who wears a dress wouldn't be considered a woman. They'd be considered a man who wears a dress, or a transvestite.

In what world do we consider people the opposite sex just for doing something stereotypically associated with the opposite sex? Can you provide any real world examples?

[Mr.Obvious]

It does if it refers to anything objectively. I could say, in my own subjective judgment, that I am sexy, but other people are free to disagree.
When people identify with a gender that is the opposite of their biological sex, there are reasons for doing it, such as them feeling that, mentally, they are the opposite sex.

But who says it refers to anything 'objectively'? I mean, trans people, as far as i understand, aren't claiming to be born in an xy-chromosone body when they are born in an xx-one, or viceversa. Indeed, the reference to being a gender opposite to that of the biological sex you are born in is by definition saying their subjective experience, (which is embedded in a cultural context imho,) is DIFFERENT from the "objective" truth.
Gender thus is of the realm of the subjective. Not the objective.
And that is not bad. That is not the same as meaningless. In fact, i find the subjective realm to be the far more meaningful one.

And your example, frankly, is bad. Because one's sexyness is also subjective and culturaly defined.
If 75% of your peers find you sexy, does that make you objectively (or universaly) sexy? If you had been a woman in the dark ages and you had pale skin and a chubby bod, you would have generally been thought of as sexy. But nowadays hollywood has influenced what is considered 'traditionally' sexy.

Edit: i think i understand now that you mean sexyness is subjective. If so, i initally misread your point. But i would still argue your argument is bad, because it misses the point entirely. And the cultural understanding of what it means to be sexy, like what it means to be any specific gender, also differs from time and place to time and place.

[Sargon The Grape]

No, a man who wears a dress wouldn't be considered a woman. They'd be considered a man who wears a dress, or a transvestite.

In what world do we consider people the opposite sex just for doing something stereotypically associated with the opposite sex? Can you provide any real world examples?

I literally addressed this in my first post, if you could be bothered to read it.

[Gawdzilla Sama]

I admit to being hopelessly heterosexual.