Jejudo, South Korea
Gender roles are cultural. To give one example: Japanese traditional culture is male dominated, extremely so; yet, it has one of the most "effeminate" cultures around.
To say that male and female roles are cultural is often misunderstood however. It tends to to make it seem that they can be undermined easily. This is not the case. Roles and identity are cultural through and through. If you want to act differently that is still culturally based. We are social animals after all.
Without culture, we are not human.
It follows that the idea of being 'real' is also misleading. The levels of testosterone in males and estrogen in women (too simplistic but I'm short on time) don't really give us enough information to establish a normative (What should a man or woman do? What are they really?) value system for either without a culture.
I know, I know, that's far too simplistic and it still gives the impression that culture is monolithic.
It's not. Still, can we make some cross-cultural generalizations?
Beer drinker and warrior have a social function outside the family.
Weaver and homemaker have a familial function outside the social.
I'm not sure how useful these are today as things are changing too quickly.