If I might seek clarification: so basically if you see some chimps holding hands, but not all chimps hold hands, and there's no factor suggesting that they should, it's a "traditional" sort of thing? i.e. they might in some fashion "love" for more than just the sake of reproduction? I'll check out that link tonight, and stay on the lookout for your crow article. I really appreciate you taking the time to elucidate this stuff.1. A courtship ritual or grooming pattern is classified to be cultural based on a few factors. A) it has to be something that is context specific (i.e., chimp x and chimp y are good friends and they always clasp hands in a certain way that they would never do with chimp z). B) it is a behaviour that is not universal and/or is diffused in a way one would expect if it was socially learned and passed down from generation to generation. C) It is something that is not ecologically determined (i.e., the behaviour can be explained away based on whether or not there is a certain ecological feature that is absent at another site).
Well it need not be "traditional." But for humans holding hands is very symbolic. I don't hold hands with anyone and I only do it in certain contexts. Holding hands is something many romantic partners do in the West, and they typically do it on dates or walks together etc. This is not the same for all couples cross-culturally. Holding hands is not the universal way couples walk together. It is something that we socially learn. It is a part of western culture. Likewise, there are certain chimp behaviours that are involved in friendship and courtship that are learned group-specific behaviours. Some will have certain hand clasps, grooming practices, or hand gestures that are only done with certain individuals in certain contexts. They represent cultural variants that can be mapped across chimpanzee populations in sub-Saharan Africa.