I think most dog owners would tell you that their adult dogs can communicate things like this, but that the language is unfortunately siloed into a very personal relationship that is difficult for even the human part of the pair to demonstrate, making it difficult to do science about
Sometimes at bedtime my cat will go to the door and scream nonstop. I don't know why he does it. Maybe it is for food or attention. But the only way I have found to get him to stop is to pick him up, put him on his special pillow, squish him, and have my partner join me in telling him "we are going to bed, it's bedtime".
I'd say about 80% of the time he listens. So he is capable of understanding what we want him to do, and capable of supressing his own personal desires in order to maintain harmony in our group. Funny enough, he won't go to bed unless both me and my partner tell him it is bedtime, so maybe he is only obeying because there is some majority consensus?
Because of this, I find it easy to believe that a cat or dog could be taught something as abstract as "self" if they can understand commands and intent and group dynamics. It's just difficult to tell what is "understood" and what is just conditioned behavior. Hell, I can't even answer that question for myself as a human.
If your cat could do most of the below:
- use arbitrary links between signifier and signified
- generate new linguistic tokens (new signifier and signifieds as well as links between them)
- refer to events and times beyond the current ones
- talk about the system of communication itself using the system itself
Then, you would have grounds to think that your cat uses a language in the linguistic sense. But until, then it is just a communication system no matter how sophisticated.
Your cat being a extremely well oiled operant conditioning system does not mean that it is able to think the way you can even if they are likely more intelligent than what we give them credit for because, as much as we would like to believe we do, we don't know what they think and any patterns that we see are just good old human pareidolia. Like hearing voices in the wind, faces on rocks, etc. Your feeling is real but the belief that feeling induces does not have grounds in reality as far as we know so far.
It is possible to over-select on skepticism about other species. Imho, the simplest explanation is that it is far more likely that there is nothing special about us, and a mere quirk of say, the combination of tool-use, foresight, and social cohesion that makes humanity special.
Or is it special? We are just a well oiled operant conditioning system, it does not mean that we are able to think the way cats can.
Laymen think of language the same way they do about theory and then try to apply that to an academic context. Different meaning. A system of communication is not necessarily a language even if all languages are systems of communication. If your dog could use arbitrary linguistic tokens, generate new ones, describe things that it has not seen before, talk about the past, the future or places other than the current one, then I would be more willing to entertain the idea that your dog has a language