I personally have little tolerance for stupidity, probably why I got into tech in the first place. I may have a better initial reaction to a pretty girl, but if she is a stereotypical dumb blonde, I quickly start talking down to her and say things like "in layman speak" - translation "I've seen smarter squirrels, so I'm going to really dumb this down for you, you petulant (because they often are) fool."
Fortunately, most blondes I knew in school were smart and completely against stereotype. I didn't have any girls in my college math courses (calc II-VI, and seriously, zero), but in pre-calc and calc my high school (accelerated math) study partner was Megan, a gorgeous, athletic blonde (she was all state in track) with a pretty nice rack to boot. Yeah, objectification there, but when I think of someone that had everything (brains and looks), I think of her. Unfortunately, she dated and mated with a dumb jock I intensely disliked and spurted out some kids right after high school graduation, so I doubt she went to college or got a job using her brains, which is unfortunate. That dumb jock did go to college (my college, which is how I know) on a football scholarship and failed out (rumors are with a 0.0 GPA, though that is possibly just rumors my friends started). I never saw or heard from either of them after that year, not that I've made any effort to look them up.