The pair discovered a total of 276 distinct facial expressions made toward other cats—not so far removed from the 357 produced by chimpanzees, Florkiewicz says, and well more than many had thought cats capable of. Each expression combined about four of 26 unique facial movements, including parted lips, jaw drops, dilated or constricted pupils, blinks and half blinks, pulled lip corners, nose licks, protracted or retracted whiskers, and/or various ear positions. By comparison, humans have 44 unique facial movements, although researchers are still working out how many different expressions they combine into, Florkiewicz says. Dogs have 27 facial movements, but again, their total number of expressions isn’t known.
In the current study, the duo found that the vast majority of the cats’ expressions were either distinctly friendly (45%) or distinctly aggressive (37%), the scientists say. The remaining 18% were—like the Cheshire Cat’s smile—so ambiguous that they fell into both categories.
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