>>24545845 (OP)I don't think there is much correlation between I.Q. and cat / dog preference.
People usually just bring out isolated examples (“Isaac Newton had a dog called Diamond!” “Albert Einstein had a cat called Tiger!”) but it would be interesting to try to do a really large-scale study. I have faith in statistics, if you get enough of them and you know what you are doing and you aren't trying to prove a particular point.
Another interesting question: how much of this preference is nature and how much nurture? You're usually going to prefer the one you're brought up with, but that's not everything. Women prefer cats and men dogs, is the cliché, and I assume there is some truth in it.
Homosexual men definitely prefer cats, don’t they? What about lesbians? Gertrude Stein & Alice thingy had dogs. On the other hand, Carson McCullers had a cat.
Oh well, doesn't mean much without at least a few hundred examples.