Maths is clearly warmer. Go look at the stats for undergrad vs postgrad. There's a huge difference. Women get maths degrees to become teachers, more or less.
Playing devil's advocate, it's possible that someone winds up getting a PhD or publishing crypto research after finding out that they really like doing math, after initially choosing it with the intent to teach.
I have absolutely no idea whether that matches reality for enough people to make any kind of a difference.