They say that imitation is the sincerest form of flattery and it appears that capuchins believe it too. These very sociable monkeys gravitate towards humans that mimic their actions, spending more time in their company and even preferring to trade with them.
Annika Paukner, who studied this monkey business, thinks that imitation is a type of social glue that binds groups of monkeys together. It says, "We are alike," and in doing so, it lays the foundation for acts of selflessness by providing a means for two individuals to form an empathic connection.
Certainly, imitation is very much a part and parcel of human life. Every day, we mimic the gestures and mannerisms of people we meet. We sit in the same way, twirl our hair, shift our accents or scratch the same spot. This "chameleon effect" is almost always unconscious and while subtle, it can have a big impact on our social success. Others like us more if our behaviour matches their own, and we in turn put more unconscious effort into imitation if we want someone to like us or if sense that we're being ostracised.
Paukner and other biologists suggest that these unconscious acts of imitation are adaptations to a social life and she wanted to see if imitation can also strengthen relationships in other sociable primates. Capuchins certainly fit the bill. Paukner allowed monkeys to play with a rubber ball while experimenters either matched their movements with their own balls or played in a different way. The animals spent significantly more time looking at the imitating human than the other one.
In a second experiment, monkeys were placed in the middle of three cages and experimenters stood in front of the other two. The animals could move freely between the cages and they spent equal amounts of time near the two humans. But after balls were brought into play, the monkeys spent more time in the cage near the imitator. These preferences translate to actual interactions too. Given a token that they could exchange for a marshmallow, the monkeys preferred to trade with humans who imitated them.
In all of these tests, it's possible that the imitating researcher was just paying closer attention to the monkeys and it was this that drew their favour. To test for that, Paukner repeated the cage experiment but this time, one human watched the monkey intently while it was playing with the ball and the other turned away; neither had a ball themselves. This time, even though the monkeys spent more time watching their watchman, they spent similar amounts of time in front of both humans. Familiarity, it seems, isn't enough - it's the process of imitation itself that's important.
However, the experiments don't tell us anything about why monkeys find imitation so compelling. Paukner suggests that it's a way of establishing empathy, but it could equally be a way of assessing dominance. Perhaps individuals who copy others are more likely to be subordinates who are safer to approach or to interact with. We still don't know what information the act of imitation conveys.
Nor is it clear how important imitation is to capuchins in the wild. For the simple act of copying to bind monkey societies together, it would have to happen fairly frequently. But while we know that monkeys can tell when they're being imitated, it's an open question as to how often they actually match each other's actions and whether they do it in the unconscious and subtle ways that humans do, rather than the deliberate mimicry of Paukner's team.
Capuchins certainly don't do copy each other to the same extent as humans do, although Paukner says that capuchins often synchronise their behaviour when they move about, forage or ward off predators. They will even pick up yawns from each other in the contagious way that humans and domestic dogs do.
If capuchins do imitate each other, and if that affects how sociable they are, then this study will surely be just the start of a fascinating line of research. Can monkeys tactically mimic each other to boost their standing in a group and ingratiate themselves with others? And if they're imitated, do they behave nicely towards just the imitator, or to other monkeys as well? Certainly humans who are mimicked behave more positively to their fellows in general - does the same apply to monkeys?
Reference: Science 10.1126/science.1176269
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