I'm sure it stems from jealously. I've seen shows where they take brunettes, bleach their hair. They then take blondes and dye their hair, having them walk in each others shoes for a while, putting them into various social situations, the results were wild. The newly bleached brunettes were paid way more attention, and visa versa. I don't think it was as bad for the "actual blondes" though because they seemed to be more confident anyway. Needless to say, brunettes have to start ugly rumors like "she's so stupid!" Don't think it's true though. Most blondes are really bleached out brunettes anyway.