Far less, actually, at least in relation to the correlation between brain size and sociability. This small brain size is, it appears, why cats are aloof, say researchers at Oxford University's Institute of Cognitive and Evolutionary Anthropology, a group who are not known to be slouches when it comes to compiling reliable and solid data that dog people can reasonably gloat over.
WebMD reports (thanks for the link, LOML) that the Oxford study surveyed 511 species to find which was the smartest and why. Those with the biggest brains are the most social; cats have comparatively small brains, which accounts for their general stupidity and their lack of sociability, the characteristic "aloofness" so frequently and so incorrectly attributed to a sign of cats' superior intelligence. Instead this "aloofness" is really just a hallmark of a dumb jerk. Cats actually rank below cows, deer, rhinoceri, most animals really.
Of course, the Oxford researchers are cowing to the powerful cat lobby (which tends to coincide with the equally powerful Harry Potter and Star Trek fan lobbies) by pointing out that they've only managed to establish a correlation between large brain size and sociability. There remains a gap, these milquetoast cat apologists point out, between linking brain size and intelligence. They did manage to spit out that chimps and humans (two of the more intelligent species on the planet) top the list for big brains and sociability. We like to hang out, we like to be smart.
Here's the definitive proof of cat's inferior intelligence that will cauterize the argument of any naysayer, a pretty good demonstration of a dumb cat (and a dumb cat's dumb family, really):
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