The graph is potentially misleading in that there is no weight for the various majors. This can be misleading just like Simpson's Paradox ( http://en.wikipedia.

The graph is potentially misleading in that there is no weight for the various majors. This can be misleading just like Simpson's Paradox ( http://en.wikipedia.org/wiki/Simpson%27s_paradox http://en.wikipedia.org/wiki/Simpson%27s_paradox ). Perhaps more men entered the field while the number of women rose as well, but more slowly, for example. The graph implies visually that the majors are of equal size and have been over time, which is not the case. (but it's hard to visualize everything together of course)