I admit that I typically like men around my age or older, BUT when setting up my matching criteria, there was a serious consideration for setting up my matching so that I would not be matched down to what I guessed to be the oldest students I encounter (easy enough to do since we don't have a PhD program, so there aren't any close to my age). It's only partially a question of being open-minded, much like I am more open-minded than other people on more superficial criteria like looks.

BTW, for men, my opinion of open-mindedness is really shown in how much OLDER he will date--not how much younger.