The role of cat eye-narrowing movements in cat-human communication

Humphrey and colleagues experimentally tested the popular belief that slow blinking is a friendly signal in cats. In one experiment, owners either slow-blinked at their cat or maintained a neutral face, and cats were more likely to slow-blink back when their owner had slow-blinked. In a second experiment, an unfamiliar experimenter slow-blinked or kept a neutral expression, and cats not only returned the slow blink more often but were also more likely to approach the experimenter's outstretched hand after a slow blink. The results provided the first experimental evidence that the slow-blink sequence, a half-closing of the eyes, functions as a positive communicative signal between cats and humans, suggesting people can use it to build rapport with cats, including unfamiliar ones.