This question just crossed my mind yesterday - you see pics of chimps grinning etc but I just wonder if there's any research into their sense of humor, expressions of it, and if it's comparable to what we experience.
Also wonder if that's really a unique genetic trait not shared with others, or that other animals have a form of it too, but we don't pick up on the (facial) clues that chimps do have.
Lastly ofcourse - what's the point of having humour? This from a evolutionary perspective: is it just a nervous tic, or a beneficiary trait?
Just curious.