[gf000]

I think one should bring into Chomsky's Universal Grammar the discussion, or at least some version of it.

If for no other reason, I believe it's quite reasonable to believe that cognition must be Turing-complete (okay, linear bounded automaton), and there must be some kind of support for recursive structures, no matter what the "primitives" of such consciousness is (either visual or linguistic).

I believe in the case of animal intelligence, they (we) have a pretty good hard-coded 3d/4d world model that ought to encode some level of recursion intrinsically (in thought, we very very often use spatial and temporal words), e.g. understanding the motion of another animal, e.g. a rodent running through a tree trunk requires imagination and future prediction already over an abstract agent. Humans just probably have more "stacks" available, and can offload them into either limited "brain memory", or very importantly drawings, text, etc, for unbounded memory.

But I'm just thinking out loud, I'm absolutely no expert on any of these topics.