Difference between "gender fluidity" and "racial fluidity"?

[GroovyGuru]

In the context of the conversation a friend of mine sort of made a harmless joke suggesting that being "gender-fluid" is no different than and just as absurd as claiming to be "racial-fluid". I kind of laughed but then started thinking about it and actually became curious to whether or not that was true and if there were other scenarios where one can just insert any category and claim to be "blank-fluid".

So I thought that there are clear differences between masculinity and femininity while there are no inherent differences between races, naturally speaking. It's possible for a woman to be more in touch with her masculine side and vice versa but you will not see a Chinese man claim to in fact be an Arab because what is exactly the difference that we can pin-point between Chinese people and Arabs (aside from culture differences)? And then one can claim that we shouldn't ignore the culture aspect and perhaps a Chinese person feels Arab because he is more in touch with Arab culture. But culture is not really dependent on actual races because you can see an individual of one particular race who "acts" in the same fashion another race typically does, whatever that means. But that would further validate the concept of gender-fluidity because perhaps (obviously) masculinity and femininity is not dependent on your biological sex.

I don't know. It's interesting to think about. What am I missing?

[LastThursday]

One observation is that gender is partly cultural. Men and women dress differently, talk differently often using different words and intonation, and have different manerisms. A lot of the cultural aspects of gender are in fact not biologically based. So just as with your insight that you are whatever culture you identify with, so it is with gender culture. For example, to a degree, although not fully I would say, a gay man may approriate some of the cultural markers of female identity: potentially make up, manerisms and intonation. But, you don't have to be gay to do this. Things are fluid, just generally not practised, the need to conform is strong.