A completely non-scientific set of results at What'sMyImage.com shows that people associate large breasts with small IQs. [[Correction added 2/22]]: Not IQs, grade point averages!]]
From the press release:
As a G-cup, it makes me think that I could have relaxed throughout my academic career. I didn't realize people had such assumptions until I was all done with a pretty impressive G.P.A. and honors and dean's list and all that – had I realized my boobs set expectations to "low" in everyone else, I could have slacked instead!