This is a good question, I honestly do not know. I do suspect this has a lot ot do with the environment. Loud clubs and poor lighting favors women with little depth of personality with the opportunity to get free drinks and low risk attention.
Of course there are alway exceptions, but in my experience I have found the hotter a woman is, the worst her personality and the less intelligent she is. In a nightclub, the noise makes it impossible to have a conversation... it goes both ways... she can hide from you the fact that she is nothing outside of her looks, and you as a man can not influence her with your words. What you say is irrelevant because what you are saying is not discernable, so she can focus on your body language and how you show up, which is a better indicator of who you really are. The poor lighting and alcohol takes away from any physical flaws she might have... you always have to remember, no matter how hot a chick is, SHE thinks she has flaws and she will spend a great deal of effort to hide whatever it is about her she does not like.