At New York Magazine‘s Science of Us blog, Melissa Dahl writes about what cats’ purring and meowing probably means.
On Purring:
The one thing you probably think you understand about how cats communicate — purring means they’re happy! — isn’t exactly right. Cats do indeed purr when they’re happy, but that’s not the most accurate translation of the sound’s meaning, Cromwell-Davis explained. “You can have cats that are happy and content purring, but also a cat that’s injured or sick will purr,” she said.
Instead, purring means something more like, don’t go anywhere, please. It’s more likely a solicitation for care, in other words, than purely an expression of contentedness. “They haven’t got a good way of asking for help — it’s not in their language — so they do the next best thing, they do the purring thing,” said John Bradshaw, a University of Bristol anthrozoologist and the author of Cat Sense: How the New Feline Science Can Make You a Better Friend to Your Pet. “The meaning is not exactly right, but it’s the closest they can get to it.”
On Meowing:
Cats and their humans develop a secret language of meows. Cats don’t really meow to communicate with other cats, Bradshaw said, which in itself is a pretty surprising little cat-fact. But in his observations of feral cats, he said, “you get a meow about once every hundred hours. They’re very silent.” And yet domesticated cats, as you know if you’ve got one, will often meow their little heads off, all day (and sometimes night!) long. “People think of it as an absolutely classic cat behavior … but it’s something they’ve learned to do to get our attention,” Bradshaw said. “It’s really something they’ve adopted as a way of communicating with humans.”
As such, there’s not exactly a universal cat language when it comes to meows. Rather, as Bradshaw writes in his book, “a secret code of meows … develops between each cat and its owner, unique to that cat alone and meaning little to outsiders.” This was demonstrated in a 2003 study by Cornell researchers, documented in Bradshaw’s book, in which they recorded meows from 12 cats in five everyday scenarios. They then played those recordings to pet owners, and found that only the owners could correctly decipher the scenario in which the meow was recorded.
For more about felines, see Dahl’s Your Cat Is Trying to Talk to You.