I like your questions.
I'm not disagreeing (unsure myself), but this talk of what "the fundamental" is, it makes me want to share about another hypothesis: that the mind's ability to operate via "recursion" is the feature from which a bunch of other things emerged. A good book that lays the case, still reading, but very thought-provoking: https://www.amazon.ca/Recursive-Mind-Origins-Language-Civili...
So if that's true, it's less about there being some fundamental core difference between us and animals. I think I agree that the same underlying drives motivate. I understand that the core drive of all life (below the particulars of our biological strata) are perhaps seeking the right alchemical mix of (1) entropy/micro-diversity and (2) cycles/periodicity and (3) compartmentalization . These drive information-creation about the environment -- mapping information of the environment into the structures "trying" to buffer themselves from change in a chaotic environment. But "trying" is anthropomorphizing (and applying false agency), and in essence, this simply allows a structure of any scale or medium to "persist" better into the next tick of the engine ;) And a structure that persists tends to have information about the environment (and the environment's future) encoded within itself. This encoding in persistent structures is what we tend to read as free-will and agency.
But anyhow, in a round-about way, I'm just proposing that perhaps "recursion" was the "new innovation" that biology of human mind stumbled upon, that really expanded the capacity to persist. And language, which not a result of new drives, fell out of that new ability of minds :)
ps, sorry for rant, i get excited about this stuff! sorry if overload, and apologies for not citing the web of readings that led me here. Happy to linkshare, if you're interested, as I certainly have sources and go back to them often! e.g.,   :)
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