Chimps are very smart. So smart they can invent new tools to deal with new situations. As a result of this different chimp groups develop different toolkits over time. This phenomena is often described as " chimp culture ". However, culture is more than just tools. Human culture features art, music, religion and so forth. In other words, it includes useless things; also known as "non-utilitarian" items. Does chimp culture also include non-utilitarian objects?
Yes, they stick grass in their ear.
That's not scientific jargon for anything. One day a chimp - called Julie - living in a wildlife reserve in Zambia stuck a blade of grass in her ear. Her group soon copied it, and before long sticking grass in the ear was all the rage in Julie's group. However, none of the other groups in the reserve picked up on the behaviour. If it was a useful practice, surely these other tribes living in basically the same environment would have independently invented it? The fact they didn't implies this is a genuine case of useless behaviour.
Now, this pointless action might not seem that significant; but it is. First it demonstrates that chimps are capable of learning from one another, something which had been debated in the past. Previously people had thought that chimps "learning" was really a bunch of them independently inventing the solution together. The fact there's no "solution" to the problem of sticking grass in your ear puts that idea to rest.
But also, useless behaviour isn't really useless. Art can identify someone as a member of a group, religion can reinforce social bonds, sports can develop teamwork. Only humans have the ability to see beyond the apparent uselessness of a practice and realise there might be something good there. Could chimp culture actually be as deep as ours? That's the tantalising possibility of this research, although it's hard to say for sure based on one example.
After all, maybe we just found a group of chimps with itchy ears.
Reference
Van Leeuwen, E. J., Cronin, K. A., & Haun, D. B. (2014). A group-specific arbitrary tradition in chimpanzees (Pan troglodytes). Animal cognition, 17(6), 1421-1425.
