@gamefreak9: There is still a gap, regardless of how much you want to play with statistics. Also, you seem to be forgetting that the world doesn't revolve around US, and most girls don't even have the opportunity to study in other countries.
That study lost me when it tries to justify the income gap with "mothers should take care of the children", with even no research on the subject. What happened to lesbians, asexual women, single/divorced/widowed women, childless women, and so on? You can't just generalize. Failing to recognize the uniqueness of each individual within a society is the biggest failure of modern "democracy".
By the way, saying that everything revolves around free will and then contradicting by talking about genes and tendencies is a giant red flag of the double standard that I was talking about. To think that we are free of any influence and that everybody makes choices in a vacuum is extremely naive. We wouldn't even dress, talk, move, act, think, and socialize this way or study in particular fields if we weren't born in the west to begin with. Even seemingly neutral things like language affect how each individual thinks, there are concepts that aren't even present in some languages. It is just baffling to think that individuals somehow exist in and make choices vacuum.