Well, you can break it down into those categories (I would, anyway). But it's more complex than that (isn't everything? lol).
Even within the Western world, you have people (I'm thinking of some feminist theorists in this case) that would challenge those basic categories.
But, what I meant was that in every society there are norms accepted by the majority of people that define what is masculine and feminine. And these aren't the same across the board. They even change through time.
For example, in the US today the majority would probably not define a real man as a male who wears lace, is well perfumed, wears make-up, a powdered wig of long hair and is well versed in romances and ballroom dancing.
But, there are also third genders or multiple gender categories that are accepted in other cultures. And it has to do with the role people take on, not necessarily their sexuality (although it may involve sexuality as well).
This is really interesting to me compared to the orthodox Western view of two genders, two sexes, two different roles, one type of sexuality and anything is else is outside of the norm.
We're seeing in this thread, too, that individuals have their own take on how they accept or reject, enact or react to those norms.