It does seem productive, science-wise and otherwise, to frame things in terms of a connective continuity between animals and humans. When it comes to communication, it's Darwin, all the way down.
Slobodchikoff: Yeah. For example, one of the things that we humans do is use body language. And studies have shown that when spoken language and body language conflict, the listeners pay attention to the body language, not to what's actually being said. So there are a lot of parallels between what we do and what other animals do. We just, for the most part, have been ignoring that because we make the assumption that other animals can't have language. So we don't look for it.
But actually, it's there, in the scientific literature. The authors of the papers I refer to didn't call it language -- but when you look at it from a language perspective, it really is about language. And we have a lot of information about it.