I've stumbled across a wonderful interview with Noam Chomsky from 1977 on YouTube, which I've bundled together into a playlist, which can be found here, or watched embedded below.
Tangentially related to things discussed in the interview, my mother said to me last night that "cats have the average intelligence of a toddler." It occurred to me that I hear many similar such things regarding animals and intelligence, and I'm not exactly sure who it is that says these things, and what they mean when they say them.
Certainly there isn't an intelligence scale from 0 to Human, with every creature ranked somewhere along the way. I don't know enough about general cognition to say for certain, but I believe that understanding "intelligence" as a monolithic trait is very misleading. If Chomsky is to be believed, then intelligence is very modular, and built for different purposes.
A cat's cognition, then, is terribly impoverished for a human, even a toddler, but particularly effective for a cat. It's like comparing apples and oranges. Strangely enough, though, I'd still want to say that humans are more intelligent than animals, and thinking so is more of a scientific fact than a cultural bias.
I think I'll try sticking more closely to linguistics in the future.