[bitwize]

Grown cats don't meow to each other. It's a noise they make to get our attention. Each cat must figure out, on their own, that meowing works to get humans' attention.

A cat with deaf human parents would have never learned this, or would have learned that meowing doesn't work and to try something else.

[vmception]

Exactly, cats have an extremely wide range of frequencies they can both create and hear, if they are vocalizing at all

They almost all independently chose to pick the signature one we associate with cats, just for us

[bitwize]

It has a lot to do with the fact that a cat's meow hits many of the same frequencies as a crying human child.

[vmception]

I’ve read that before, it engages well but I’m not sure they all know what human babies sound like, it just gets a reliable response and other frequencies are either ignored or don’t get then the response they like the most

[bitwize]

Yeah, cats don't necessarily know that, they stumble across it by trial and error. We respond to it because we are to some extent hardwired to have our attention grasped by that kind of sound, so we tend to our crying babies.

[arethuza]

"works to get humans' attention"

Our cat manages to make a noise that sounds like a young child screaming "mum" - it really upsets my wife.

[AlotOfReading]

Cats definitely meow to each other. For adults it's typically an aggressive warning, but it happens.

It's also worth noting that kittens and their mothers communicate heavily via meows even when no humans are present. Food-begging is a pretty straightforward association from there.

[throwanem]

Cats don't meow as a threat. They growl. The varying tones and pitches in which they do so carry information of their own, and sometimes are in similar ranges to a meow. But listen closely to the timbre and intonation next time you find the chance, and you'll probably find yourself able to notice how similar the two sounds are not - not least in that a growl carries much more information.

You're right that meows are by default how cats talk with their kittens. They also bring kittens dead or nearly dead prey, as the first step in teaching them how to hunt. That they choose to use the same idioms with us I think constitutes an eloquent comment on how clever they find us.