Silly cat faces might entrance you online, but how do they engage you in real life? Not so well, it seems. That’s the conclusion of researchers who recently developed an intricate index of every feline facial expression possible. They found that—no matter the doe-eyed demeanor or grumpy grimace—a cat’s countenance didn’t make any difference in whether it got adopted from a shelter. Instead, fur babies boosted their chances of finding a home by rubbing on toys and furniture.
But why study cat faces to begin with? In 2013, evolutionary psychologists found that shelter dogs who raised their brows more frequently were adopted more quickly than other dogs. A dog who raised its brows 20 times while meeting a human found a home about twice as quickly as its peer who only did so five times. Researchers concluded that the brow raises made even older dogs look puppylike and friendly, a trait that would have made them more appealing to humans during their millennia-long domestication.
Curious whether cats do the same thing, those same researchers developed something called the Cat Facial Action Coding System. The system—based on similar programs for humans, chimps, macaques, gibbons, orangutans, and dogs—encompassed every possible facial movement a cat could make, based on its musculature and anatomy: fifteen facial movements, seven ear movements, and six other movements involving the tongue, lips, nose, eyelids, or pupil. The scientists then came up with a list of common facial expressions and body movements, based on visits to 106 cats across three animal shelters in the United Kingdom.
Next, they tracked how quickly the cats were adopted, looking for statistical correlations between their facial expressions, movements, and adoption speed. Unlike dogs, felines weren’t adopted any quicker because of their facial expressions. However, cats that frequently rubbed their bodies on toys and furniture inside their pens were adopted about 30% more quickly than cats who didn’t, the team reported recently in Applied Animal Behaviour Science.
That means that, compared with dogs, cats haven’t faced as much evolutionary pressure to appeal to humans, the researchers say. That might be because they only started living near humans relatively recently, and because they were domesticated thousands of years after man’s best friend.
Dennis Turner, an evolutionary biologist who studies companion animals at the Institute for Applied Ethology and Animal Psychology in Zurich, Switzerland, says the experiment only loosely resembles real-life adoptions, so more work needs to be done before he’s convinced. But if cat expressions do play a small role, he wouldn’t be surprised. “I seriously doubt that cat facial expression was subjected to selection during domestication,” he says, because humans kept cats around to catch vermin, not to be bosom buddies. “If facial expression was selected for at all, it was during the last 200 years during the development of different purebreds.” Those are rarely the animals being adopted from shelters, he adds.