For both classes, the students segregate themselves by sex. One long row of girls with clusters of guys around them in one class and in the other, guys on one side of the room and girls on the other. Except there are only two guys in that class so it is oddly lopsided, with girls extending all the way to the back of the room when they could just sit on the "male side" of the room, closer to the front.

It's possible of course, that these girls just prefer the back but I am inclined to think that they self-segregate.

contemplating possible explanations for this phenomenon...