Research indicates primates may follow arbitrary trends, just like their more evolved cousins.
image via (cc) flickr user photogism
When it comes to following useless fads, we Homo Sapiens might not be the only game in town.
That, at least, is what researchers surmise in a paper published for the Journal of Animal Cognition. There, The Max Plank Institute’s Edwin J. C. van Leeuwen, Katherine A. Cronin, and Daniel B. M. Haun describe a troop of Chimpanzees Leeuwen was studying while in Zambia. One day Leeuwen observed a chimp nicknamed “Julie” inexplicably stick a long blade of grass into her ear, where it remained as she went about her otherwise mundane ape-y business. Before long other members of Julie’s troop were beginning to stick blades of grass in their ears as well, a trait the team appropriately dubbed “Grass-in-ear behaviour” (GIEB). By the end of the multi-year observation period, the majority of that troop had GIEB’d on multiple occasions, including a number of times after Julie herself had died. The researchers then compared the observed behavior with that of other nearby (and therefore environmentally similar) chimpanzee troops, and found almost no instances of GIEB. This wasn’t something apes in that area simply “did”. It was, instead, something Julie’s troop, and only her troop, had adopted for themselves.
As the Wall Street Journal’s Robert M. Sapolsky points out, transmission of “culture” between apes and monkeys has been a feature of primatology since the 1940s. What’s new here, he explains, is that the behavior observed in Julie’s troop doesn’t serve to help the chimps eat, mate, or defend against predators. It’s entirely, almost laughably, arbitrary.
Or, as Leeuwen and his team put it in their paper’s conclusion:
Regardless of the precise mechanism underlying the behavioural diffusion, our observations importantly show that chimpanzees spontaneously copy arbitrary behaviour from their group members. [... W]e interpret our data as reflecting chimpanzees’ proclivity to actively investigate and learn from group members’ behaviours in order to obtain biologically relevant information. The fact that these behaviours can be arbitrary and outlast the originator speaks to the cultural potential of chimpanzees.
Or, put another way: primates will often copy one another’s behavior for good (that is “biologically relevant”) reasons. Sometimes, however, they’ll follow a trend that displays a discernable purpose simply because, well, it’s a trend to be followed.
Monkey see, monkey do.
image via (cc) flickr user tambako