A few years ago, a trend led people to test the theory that you could know if a smile was real or fake by examining the eyes. Squinty, wrinkly eyes meant the smile was genuine, while eyes that lacked wrinkling indicated the smile was insincere. The Duchenne smile became defined as a smile that involved the muscles surrounding the eyes as well as the upturning of the lips, according to the American Psychological Association. “Duchenne smiles are believed to be authentic smiles, as opposed to posed, voluntary non-Duchenne smiles that lack the orbicularis oculi component.”
But before judging a non-Duchenne smile as insincere, a 2021 study by Carnegie Mellon University tested the theory and concluded that eye wrinkling may have more to do with the intensity of the feelings behind the smile, not necessarily the sincerity of the smile.
The Duchenne smile is a popular study of human psychology, but it turns out that cats also have their ways of smiling, and it involves expressing and reading emotions through the eyes.
A Kitty Smile
Cats are prolific communicators and have many modes of communication. They communicate with their voices, mostly to their humans. They communicate with their ears and tails and by rubbing their pheromones onto things. They communicate with their eyes with each other and with people.
Among cats, closing their eyes in the presence of other cats is a sign of trust and that they can be trusted. They are communicating their trust in the other individual and that they themselves are no threat.
When your cat closes his eyes slowly at you, he is demonstrating contentment, security and a relaxed state. It is the closest thing to a kitty Duchenne smile. And when you return a slow blink to your cat, you’re smiling back.
A groundbreaking study published in the Oct. 5, 2020, issue of Scientific Reports, suggested that slow blinking is a form of positive communication between cats and humans.
The researchers conducted two experiments involving 21 cats and their caretakers from 14 households in the first and 24 different cats from eight households and total strangers in the second. The people who participated in the second experiment had no prior contact with the cats, and when they slow blinked at the cats, they also extended a hand to them.
The researchers noted that the cats delivered more slow blinks to their caretakers if their caretakers were slow blinking at them but not if their caretakers were simply in the room and not slow blinking. Even when the total strangers slow blinked at the cats, the cats reciprocated with eye narrowing movements. And when the strangers extended their hand, the cats were more likely to approach the strangers following slow blinking interactions than if the strangers had kept a neutral face and made no eye contact.
The study results confirmed that cats’ slow blinks appear to express positive emotions, but further research is needed to draw solid conclusions. Possibly the first study of its kind to investigate the role of the slow blink in feline-human communication, the results do appear promising that the behavior indicates positive feelings.
“Such findings could potentially be used to assess the welfare of cats in a variety of settings, including veterinary practices and shelter environments as well as enhancing cat-human communication in the human home,” the researchers wrote, adding that this is still an under-studied field of research.
Those of us who have lived with cats for a long time know the look when our cats slowly close their eyes and offer us an expression of utter contentment. It’s a look that invokes in us feelings of happiness and reminders that we all need to relax and smile more.