This tell-tail sign means your cat likes you

How well do you know your pets? Pet Psychic takes some of the musings you’ve had about your BFFs (beast friends forever) and connects them to hard research and results from modern science.

WHAT DOES THE PHRASE cat communication make you think of? Probably a meow—or a hiss, if you’ve ever crossed a kitty’s boundaries. Yet much of what cats “say” to each other and to humans isn’t expressed out loud. Rather, it’s conveyed by their tails.

There’s the side-to-side swish when they’re agitated; the straight-down, puffed-out position of fright; the horizontal line for neutrality; and many more back-end gestures shared among the feline family. But one movement is largely confined to adult domestic cats: tail-up, whereby the articulate appendage is held perpendicular to the cat’s back, with the tip pointed forward at an approaching individual.

“You look at all the other wild cats in the world and they all have very similar mannerisms and behaviors. [The tail-up signal] is specific to domestic cats and to lions,” says Sarah Brown, a cat behavior specialist and author of The Hidden Language of Cats. “I think that’s just amazing.”

In the early 1990s, Brown tracked the behaviors and relationships of a free-living cat colony in Southampton, England. She observed that the tail-up position preceded amicable interactions, with cats often affectionately rubbing heads and sometimes sitting together afterward. Subsequent studies by researchers elsewhere bore those observations out. In tests where cats were presented with images of felines whose tails pointed up or down, the tail-up pictures elicited friendlier responses.

It’s also been demonstrated that cats use the tail-up cue in a similar manner with their humans—attentive kitty keepers may have already come to this conclusion. But it’s less evident where the expression came from. How did our lap-loving, couch-climbing companions end up sharing a behavior with the so-called king of the jungle? 

Black cat walks down hallway with tail up. Red filter on photo.
Charlie models the tail-up position in the company of his doting humans. Julie Blindauer

Even Felis lybica, the African wildcat from whom domestic cats evolved, makes the tail-up gesture in kittenhood. That’s a telltale sign of an origin in their domestic history, which is thought to have started about 10,000 years ago as wild cats congregated to hunt rodents around the fields and storehouses of Mesopotamian farmers. There they lived in closer proximity to one another than ever before.

Suddenly, cats had a pressing need to negotiate social interactions. Having an easy-to-read pose that quickly conveyed approachability and ease would help them avoid unnecessary conflict. Natural selection would “favor this behavior because it improves the cohesion of that social group,” says Eugenia Natoli, an evolutionary biologist who has studied the behaviors of free-living cats in Rome. “The reproductive success of individuals who cooperate would be higher than the success of individuals who don’t cooperate. It would then move on to the next generation, and so on.”

Some scientists have even suggested that tail-up evolved in captive-bred colonies of ancient Egypt, where cats were sacred and also sacrificed in mind-boggling numbers—an estimated 385,000 feline mummies were buried in a single temple. These large-scale rearing facilities would likely have been a crucible for new adaptations to communal living.

Whether this body language started on farms or in cat mills, we may never know, but both possibilities dovetail with its presence in lions, who typically live in prides with up to several dozen individuals. Other cat species are mostly solitary: They may have consistent relationships—mountain lions, for example, belong to complex hierarchical societies—but they’re not spending much time together.

Only domestic cats and lions share that life history. However, if sociality can explain the evolution of the tail-up signal, here’s a question: How did cats settle on that rather than some other behavior to convey good vibes?

At some point, cats took the small leap to pointing their tails at their favorite humans.

There are three possible answers so far, summarized by Brown in her book. According to one, tail-up was a riff off the crouching, haunches-raised sexual displays of female cats. The second idea is that it originated from the tail position that cats use when spraying urine to mark their territory or send a message to neighbors. The last hypothesis suggests that it comes from the movements kittens reflexively make when approaching their mothers.

“As soon as they become mobile and Mum’s coming toward them, that little tail goes up,” says Brown. “They all do it.” Precisely why is another mystery. Natoli thinks it’s a biologically hard-wired way of helping mothers identify kittens by smell—cats have scent glands on their flanks and tails, and by lifting their tails, they make these easier to sniff. But both she and Brown think the third explanation for the tail-up origin is most likely.

“Perhaps [solitary wild cats] didn’t meet many other cats once they left their mother. They got out of the habit of putting their tail up. But [domestic] cats today are so constantly surrounded by other cats or people, they just carry on doing it,” says Brown.

That would make tail-up a neotenic behavior—one that is performed early in life and continues during adulthood. Kneading—when nursing kittens and snuggling mature cats flex their paws—is another neotenic behavior. (This one may be shared across felines.) Tail-up has positive emotional associations for a little one who’s happy to see Mom, and it could retain those associations for grown-ups.

At some point, cats took the small leap to pointing their tails at their favorite humans. Over a 10,000-year history, we became members of their group. They chose to befriend us—and they remind us of that every time that tail forms a furry thumbs-up.

Read more PopSci+ stories.