speaking of gender

I've noticed, here at the AEA convention, that in the seminars in which enough women are in attendance to actually ascertain a seating distribution, they sit disproportionately towards the back. And, since these are usually the same seminars that are full, this is not the same seating distribution as for men.

I was surprised by this since it counters my sexist prior that women tend to be more diligent goody-goodies and therefore more often prefer to sit at the front*. Is this no longer true among women who have selected into the profession of economics? Is it no longer true after a certain age? Why the switch, rather than simply a convergence in seating preference across genders? Is it just because they arrived earlier and took the rear seats, preferred by all? (I doubt that, since the emptier seminars I attended were not fuller at the back at all.) Is it just a fluke?

*which contributes to my typically contrary desire to sit at the back (in addition to the much stronger factor of wanting to fly under the radar in general...)