I heard once that laughing is an evolved behavior that basically communicates "everything is ok between you and me" so you ease into the relationship and the bond strengthens. But I have to really stretch to reach "and monkeys also massively rib to the point of embarrassment and at great potential cost to themselves." I certainly get why it's fun. But why it's so pervasive is just surprising.
The evolutionary advantage of Homo Sapiens over Homo Erectus or Homo Habilus or Homo Neanderthalensis is our ability to use language - sinuses exist for better communication. the sapiens palate is better evolved for communication. Our forebrains are evolved for better communication. The tribal hierarchy practiced by sapiens allows for more sophisticated herd behavior which gave us an efficiency advantage over everyone else. If I haven't recommended this book to you before, I am now correcting that deficiency. Fundamentally, humans don't have the jaws to eat raw and without the ability to cook food we perish... but by evolving the ability to cook food, we were basically able to develop the animal kingdom's first external digestive system. Doing so allowed us to run fast, run lean, and run brutal in ways other animals can not but putting such a vital biological function out in the field instead of inside the ribcage required a communal-insect-level commitment to societal structure. It's only been recently that biologists have started listening to anthropologists: anything that strengthens social bonds is of evolutionary advantage. Full stop.
This breaks the hearts of the old anthropologists. My thesis adviser, on the one occasion that I heard her complain about anything, bemoaned the fact that she was entering into her 70's right as the field has begun to be taken seriously.It's only been recently that biologists have started listening to anthropologists: anything that strengthens social bonds is of evolutionary advantage. Full stop.