I was only talking about a possible statistical difference, which might be that significant. A quick search lead to a paper[1] which says the average is ~110, which is not insignificant. In my perception the 'left' side states that there is no other factor than bias against women ( or I haven't seen any other argument ). The original document here stated that sexism exist but there might be other factors too, and apparently that was a problem. [1] http://www.ssc.wisc.edu/cde/cdewp/98-07.pdf