Genders or societal influence?

So here's something that's been floating through my head. With all the LGBTQ stuff it's been said many times that the individual did not "feel like the gender they were born as" but without society's influence what would "man" and "woman" really mean in terms of behavior? Without magazines and movies and ads to show us the accepted behavior for the gender in question what would it even mean to be male or female? Do they truly feel like they were born with the wrong genitals or do they feel like they don't fit into the accepted behavior pattern for that gender? Is it really biological or just bucking the system?

There were men and women before society. They wore whatever they could taken from wherever they could get it. They simply survived. They didn't wear jeans or dresses. Our definitions of male or female wouldn't even apply to men and women pre society. We made it all up. It's a fabrication, a fable, a fiction, a stage play. There's no link to history or reality in any of it. In fact most of what we accept in terms of behavior for the genders was taken from animals and not humans. This makes me wonder if they truly feel like the opposite sex or if they simply don't feel right "playing the part"...

Thoughts?