If you sit down next to a cat, and throw your arm over the back of the sofa while someone reaches over from behind and starts to pet the cat, and then after a little bit you stand up and leave while the phantom arm is still petting the cat, the cat understands that something really freaky is happening, gets scared, and runs away.
I would have thought they’d be happy that whatever weird thing is happening is petting them, but apparently not. An arm with no human is alarming and bad. I think it’s cool that their mental model is that similar to ours.
Mammals in general are so smart that I wonder if this mental model is shared by the whole class, or at least the Boreoeutheria (clade that includes both carnivores and primates, plus a lot more critters). And, like, the evolutionary benefits of that model are obvious - if whatever tore your arm apart is still lying around, you need to run away ASAP.
Birds are very smart too, some of them are much smarter than the average mammal.
I remember an article not long ago about a songbird that “riffs” within its song. Something like a jazz musician might. I’m fuzzy on the details, but this was stated as a sign of intelligence. The theory is that neural density might be variable based on the species…or something. Basically even that a bird brain can be intelligent and capable of some level of free thinking. We all know about crows and their street smarts too.
Some of them are really smart indeed, and I wouldn’t be surprised if they developed a similar mental model through convergent evolution.