Mmm.
What do you mean about the animal kingdom? Male penguins incubate eggs, male seahorses get pregnant. Dogs of both genders mount each other. And none of them (so far as we know) have the consciousness it takes to make active decisions about identity and behaviour.
So, given animals don't give us a clear picture of 'males do this and females do that,' surely it is ok for us to accept who we are?
If there were demonstrable masculine and feminine traits, I would have no issue with them existing ... but what I do have an issue with is testing the current population, which is in a skewed situation, and claiming the resulting trains must be innate and cannot be conditioned.
For example, some (very poor) scientists decided to 'test' for the feminine trait of preferring pink ... they believed this must be innate because, of course, at the dawn of time women needed to spot pink berries in their role as gatherers. 
Another test found that female babies were 'instictively' nurturing and preferred 'feminine' toys ... though the researchers knew which babies were boys and which were girls while they performed the tests!
It is extremely hard to perform tests that would demonstrate innate gender differences. If we lived in a world where gender didn't matter, that might be ok, and no more than an interesting difficulty for scientists to ponder. Given that we live in a world where women suffer purely for being born female, it matters a lot and therefore, the fact the results can only ever be very uncertain is something that's important to recognize.