Where does this myth come from anyways?

It's unfortunate, because those stereotypes cause women to dismiss brainy/nerdy types perhaps too quickly... As for myself, I am a 5'7" nerdy type, so I assume that most women who believe in this myth would not expect to find anything of significant size in my pants... well, they would be wrong (8"x5.75")!

So thanks for helping disprove this myth once and for all (and please DO tell other girls!).