Bleh
Blah
The fact that it's a cultural construct doesn't invalidate it entirely. Culture is an extremely powerful thing.
I agree with you, and never said it wasn't. That's irrelevant here, though; Culture is still a fundamentally separate entity than Biology, and though they operate on surprisingly similar laws, arguments that impose a culture-based code of conduct on people as though it were "the natural way of things" need to check themselves, lest they wreck themselves.
(In other news, I just realized the connotations of using Swing for my "gender roles = dance" metaphore. No that wasn't intentional; I meant it literally. Nevertheless, >_<
Femenine and Masculine are constructs of culture and not biology.
No. "Masculine" and "feminine" are primal forces that exist on a pre-conscious level. I've given many examples of masculine/feminine relationships that exist in non-biological and non-cultured things. Rocks and canvas, and so forth.
It is a mistake to assume that "man = 100% masculine and woman = 100% feminine." But it is also a mistake to suppose that these fundamental forces magically don't apply just because we happen to be complicated human beings with the capacity to choose.
To think that masculine/feminine requires society, culture, biology or humans at all would be a misunderstanding of masculine/feminine forces. When water erodes rock...that is a masculine/feminine exchange.
As the study of Biology, Culture, and what it is to be Human, are the subjects I've devoted my life to learning, allow me to illustrate why you are wrong.
For starters, you're taking a poetic and spiritual metaphore for interactions between two objects, which is considered in some traditions to be a cosmic force which governs all events in the universe, and using that as the foundation of your argument. I will not debate the significance or reality of Yin and Yang here, but please realize your argument is based on Dogma. Say I had an equally strong Dogmatic conviction that ran at odds with yours... perhaps that I followed the Vedic tradition, and identified as
Tritiya-Prakriti... we could argue indefinitely. That's because Dogma is based on personal convictions and presupposes the existence of Final Causation. It is not a substitute for Logic.
Stepping outside the realm of spirituality for a moment, allow me to point out how gender is a relative thing, defined by the culture you were born in. To the Yanomamo of South America, you are not a Man, nor am I a Man. Riddick from Pitch Black might be considered a Man, but only because he's a violent, backstabbing douche. Theirs is a culture that idolizes ferocity, posturing, and standing up for yourself through acts of aggression (though these usually end before open violence). A Man in their culture is expected to steal from their neighbor if you thought they wouldn't retaliate... and this would considered your neighbor's fault for not scaring you off. In their culture, it's the duty of a Husband to beat his Wife viciously, because it helps protect their family; their husband looks more frightening and powerful when he's willing to hurt his Wife over trifles, and thus is a Man worthy of respect and power.
So yeah, you and I would not be considered Men to them, nor would we be Women. We'd occupy some weird Third-Gender between the two, would most likely never be able to Marry or rise to any position of power, and would generally have no place in their society. Interestingly, it's not unlike how Western culture has historically treated people who don't fall neatly into the gender roles it provides, such as "passive" or "feminine" men. However, just because you don't qualify as a Man to the Yanomamo doesn't mean that Western Culture would view you any differently than it does now... whether you are or aren't a Man all depends on who you ask.