For most of people, the intuition of intelligence is a bit naive, and nowadays intuition is often at the opposite of the truth. It often is along the line of "looking intelligent and knowing what it is doing”. Something like turing test describes the first part intuitively. But we soon found out that we wouldn’t call something “intelligent” even it passes turing test since the machine is unlikely to know why it is saying something, hence the latter part. But again, this is about consciousness or “strong AI”, which is even further away from our understanding than “intelligence”. How do we know that the machines that “look intelligent” don’t “know what they are doing”? Consciousness is very hard to define and even harder to inspect, and maybe someday machines begin to have consciousness even before we realize it? In fact, we already did this to most animals, thinking they are not intelligent or self-conscious while they are.
But to me, the psychology behind these definitions is very interesting and maybe quite important. No matter how we try to define intelligence, we wouldn’t call machines intelligent until they very much behave like us. Because to most people, intelligence is what defines humans, so they intuitively use their feelings of “does that feel human” to benchmark intelligence. And psychologically, we are exceptionally good at telling something “not human” from “feeling/looking/speaking like human”. But this is a very narrow and, if I dare to say, ignorant and self-centric view, because it implicitly relies on the thinking of “we are far more intelligent than any other life form, and human's intelligence is the only way intelligence can be work”.
Think about it, if there’s a super-intelligent being that observes our world, maybe to it, human’s intelligence is as primitive as fish, and trees aren’t far behind; and maybe, entities such like countries or the internet are actually of more intelligent “life” forms, just we haven’t realized that yet because they don’t look like us at all; and maybe, on the scale of intelligence from 0 to that super-intelligent, humans, birds and machines are clustered in a small range, though significantly larger than zero, still not far from it.
Although the research on human brains and a lot of our own stuff inspired the research of AI quite a lot, it is perfectly possible that we create something truly intelligent or conscious without us understanding human intelligence or consciousness fully. We can have a different kind of “intelligence”, and our researches are well on their way toward that. It’s very hard to see because we don’t understand intelligence, and maybe our hardware isn’t powerful enough to fully utilize our theories.