Ygrec - I'm actually glad you mentioned this because boy and girl are not even generalizations. We just don't hear about the other cases. There are plenty of cases of hermophrodites. There are females with only 1 X chromosome which menifests as Turner's Syndrome. In the opposite case some women can have 3 X chromosomes. There are boys who can have XYY chromosomes as well as XXY chromosomes. Sometimes these can have no outward showing of physical abormalities and some can cause women to have very broad shoulders and necks like men but still be women.

My point is that even with broad generalities like boy and girl.....those are even generalities anymore. There are so many other types of chromosomes that people can have that put them somewhere in the middle.