I've read there's also a social aspect - crows are extremely social creatures, as are humans, and other highly intelligent animals like whales. That does seem to be a common denominator.

Regarding that, I'm reminded of another story - on my daily walk near work, there was a dead crow on the pavement. 5 or so crows were standing all around it, doing nothing really. Even me passing close by did not trigger them to fly away or anything, it seemed like they were standing watch on the body. The next day, it was still there, same thing. The 3rd day, it was gone, but the crows were still standing watch in the same manner. I didn't know what to make of it other than it appeared they were mourning or taking part in some type of ingroup ritual. I didn't see it again after that, but it struck me.

Corvids have been known to investigate deaths, truly fascinating creatures!

https://www.sciencedirect.com/science/article/abs/pii/S00033...

> [Social creatures] does seem to be a common denominator.

One theory is that it drives the creatures to internally model or simulate others intents and reactions, in a way which is a far more regular, consistent, and nuanced than any modeling of various prey or predators.

Further along that path is modeling future-me in plans, and layers of "I know they will know I know they know, so..."