There are other things interesting about this graph too.  (1)  The overall increase in the percentage of the U.S. population who attends and graduates college… and thus changing ideas about who “needs” a college degree.  (2) The fact that the gender difference wasn’t extreme in the late 1800s at all and increased in the early 1900s. (This is in contrast to most students understanding of history, in my experience, as a linear story of progress from backwards to enllightened.)  (3)  The spike in college enrollment and graduation after WWII (GI Bill… but how does that explain the stats on women?).  (4)  The weird dip in 1950s (I don’t know what that’s all about).  And, (5) the period of near parity in the 1960s.  (In the comments, Penny points out that I mis-read the graph in haste.  I apologize.)   (3) The weird dip for people born in the 1950s and coming of age in the 1970s (I don’t know what that’s all about).  And, (4) the period of near parity for people born in the 1960s and coming of age in the 1980s. 

See the accompanying article at the New York Times.