Thirty-one Japanese house cats recently participated in an experiment. Animal behavior researcher Saho Takagi recruited 23 of them from cat cafés near Tokyo, and eight friends volunteered their pets: 20 tomcats and 11 queens, most of them roughly around the age of 4.
Takagi traveled from one cat’s home to the next. In a room familiar to each cat, she placed the feline gently onto her lap, then watched where the cats directed their attention as a monitor played back a videoclip Takagi had carefully composed. In the clip, a cartoon of a smiling red sun, complete with eyebrows, shrank and expanded into view, accompanied by the word keraru spoken loud and clear by the cat’s owner.
Keraru is meaningless in Japanese, but Tagaki believes the results of her experiment show that cats can understand human speech to a certain extent. When presented with the sun, the cats paid attention to the video for 3 to 5 seconds. The researchers repeated this pairing of the sun and the word keraru several times, to encourage habituation. But when cat owners later spoke the word keraru alongside a drawing of a blue unicorn smashing through a building, Takagi found that cats stared at the screen for longer than usual, as if surprised that “keraru” had so dramatically changed appearance. She believes they had learned to associate the word keraru with the image of the sun.
The study borrows its lively methodology from experiments probing cognition in human babies, who at 14 months appear to be able to make associations between words and objects, and, much like the cats, also pay closer attention to a screen when these associations are challenged during the course of a study.
Cats can differentiate between their own name and similar-sounding nouns.
A behavioral scientist researching animal cognition at Azabu University in Japan, Takagi is convinced that domestic cats are adapting to life with their human companions in surprising ways. The results from her study, published recently in Scientific Reports, also show a difference in attention that cats pay to the videos depending on whether the accompanying words are narrated by their human owners, or produced electronically. The cats paid closer attention to incongruent image-sound pairings when humans spoke the words.
“Cats may have acquired the ability to associate objects or images with spoken words through their cohabitation with humans,” says Tagaki. “Humans, among animal species, have a particularly rich capacity for vocal communication, especially symbolic communication through language. Being in close contact with such a species … cats that were better at symbolic communication may have been more favored” over time, she explains.
Part of her hypothesis is that domestication played a role in pushing for the evolution of this behavior in cats. Similar findings exist for pet dogs, who on average understand 89 spoken words, but they are less surprising since dogs are thought to have been domesticated specifically to respond to human commands. Cats are a more enigmatic case, since their domestication would have brought few clear benefits to humans beyond a fondness for snacking on snakes and mice.
The new findings build on previous research that suggests cats are adept at deciphering human communication. Takagi’s studies have shown that cats can differentiate between their own name and similar-sounding nouns, whereas other groups have shown that cats follow human pointing, look for emotional cues from their familiar humans when confronted with novelty, and can tell when their owner is angry or happy.
“I think the way cats have adapted to living with humans is very unique,” says Jennifer Vonk, professor of comparative cognitive psychology at Oakland University, who was not involved in the study. But Vonk is less convinced by the approach scientists are taking to understand the evolutionary changes that may have occurred through domestication. For Vonk, the inferences made are too reliant on a human-centric projection of what may be happening in our pets’ minds. “Even if we can get the [cats] to perform in the test the way we want them to, they could be using completely different thought processes,” says Vonk, “and I don’t know how good we are at deciphering what’s really going on internally.”
A better test perhaps would be to compare domesticated cats with their feral brothers and sisters, Vonk says. Better still, the most rigorous study would see cats separated from their mothers at birth, with some siblings exposed to humans and the rest forced to live without such contact. “But there are ethical issues with doing the study,” says Vonk.
That’s not to say that Vonk doubts the power of cat intelligence. “I think that cats and most animals are much better at reading our cues than we are theirs,” she says, “so I am guessing they are more skilled at understanding our language and our emotional tones and posture than we are at reading their behavior.”
Could it be that cats domesticated humans, rather than the other way around?
Lead image: Nils Jacobi / Shutterstock