If you think your cat has few or no facial expressions, pay more attention to its face when interacting with other felines. The social life of cats is quite intriguing.

How these animals befriend each other and form a bond is still a mystery, even for scientists. To delve deeper, a team of international researchers recently conducted an interesting study that explored rapid facial mimicry (RFM) in cats using an AI program. RFM is an involuntary social behavior where an animal copies the facial expression of another animal.

It is thought to help with social bonding, communication, and understanding emotions. For example, a father mimicking his toddler’s facial expressions to make them smile. Similarly, when one chimpanzee playfully opens its mouth, another chimpanzee often does the same gesture almost instantly. This helps reinforce social bonds and signals a friendly interaction.

Previous studies show that apart from humans and apes, horses, birds, and dogs also exhibit RFM. Here’s how the study authors spotted this behavior in cats.

Catching the subtle cat expressions

A previous study by the researchers found that cats can display 276 different facial expressions. Of these, approximately 37% are linked to aggression, while 45% convey a friendly demeanor. This time, the study authors delved deeper, examining how a cat’s facial expressions change when it closely interacts with another cat. 

The researchers studied how domestic cats interact with each other in social settings. They first recorded videos of these interactions in one of Los Angeles’s cat cafes and then trained an AI program on these videos. Once the program was ready, it could closely examine and track the facial expressions a cat made using 48 virtual dots (landmarks) on its face.

The study builds on earlier work by Lauren Scott and Brittany Florkiewicz, who developed the Cat Facial Action Coding System (CatFACS). This system, akin to a feline version of the human Facial Action Coding System, breaks down cat expressions into discrete movements, such as ear twitches or lip curls. Using CatFACS, the researchers analyzed 186 communicative events among 53 cats at a Los Angeles rescue lounge.

The program identified 26 new facial movements, resulting in hundreds of expressions. When the AI categorized these variations, the researchers noticed that out of 100, about 22 times, cats mimicked each other’s facial expressions, especially during affiliative interactions like grooming or playing.

“About 22% of the time, the felines mirrored each other, often within a fraction of a second. The mirrored expressions were subtle, sometimes just a modest flattening of the ears paired with a small wrinkle of the nose or a tiny raising of the upper lip,” Teddy Lazebnik, one of the study authors, told Science.

“But when they happened, the cats began a friendly interaction—playing together, grooming each other, or walking together—almost 60% of the time,” Lazebnik added.

One of the most intriguing findings was the role of ear movements in rapid facial mimicry. Cats frequently mirrored each other’s ear positions, such as rotating or flattening their ears, during affiliative interactions. This strengthens the notion that ear movements are very important for feline social signaling.

The study also found that certain facial movements, like parting the lips or dropping the jaw, were more likely to be mimicked during playful interactions. These movements, often associated with “play faces,” may help cats coordinate their behavior and avoid misunderstandings that could escalate into conflict.

RFM can help us help cats

There may be some practical applications to these findings. For instance, by identifying cats that exhibit high levels of rapid facial mimicry, shelters can make more informed decisions about which cats to house together, potentially reducing stress and conflict.

“Using AI to monitor cats’ RFM holds a lot of practical potential, especially when it comes to understanding their reactions and needs, preventing conflict, and improving their well-being,” Brittany Florkiewicz, one of the study authors and a psychology professor at Lyon College in Arkansas, said.

Cats aren’t as aloof and solitary as stereotypes might suggest. So the next time your cat flicks its ear or narrows its eyes, take a moment to notice.

The study is published in the journal Scientific Reports.