Imitation in Monkeys and Apes

Almost all animals learn novel tasks more easily if they can observe a knowledgeable demonstrator Biologist Tom Langen trained individual magpie jays to pry open a door on box that contained food. Subsequently, birds whose social groups included a demonstrator learned how to open doors much more rapidly than birds whose groups did not Indeed, birds in groups that lacked a demonstrator did not even realize that there was food in the boxes Similarly, in captivity, many monkeys can learn to use rudimentary tools to obtain food, and they do so more quickly and accurately in the presence of a demonstrator. If monkeys learned like humans do. it would be safe to assume that the monkeys learn to perform the tasks by watching the demonstrator and imitating his actions. This would imply that the monkeys understand the demonstrator’s intentions and goals. But this does not seem to be the case.

Most animal species show very little evidence of purposeful copying by imitation. In the laboratory, monkeys are attracted to tools and often begin experimenting with them after observing another monkey do so, suggesting that social companions enhance and facilitate tool use. But learning about a tool’s use through”social facilitation” typically requires extensive practice through trial and error. As a result, different individuals adopt different idiosyncratic styles, and the spread of the skill is very slow. Although many monkey species can learn to use tools in captivity, there are very few examples of tool use in the wild. Capuchin monkeys, which inhabit Central and South America, are the only monkeys that regularly use sticks or stones to pry into trees or break open nuts under natural conditions. Capuchin also have comparatively large brains compared to other monkeys. The relative lack of spontaneous tool use in monkey species suggests that monkeys have difficulty recognizing the relation between actions and objects.

In the wild, baboon monkeys seem to use tools only in aggressive contexts. When displaying, male baboons occasionally wave or throw sticks in the direction of their rivals. Whether they recognize the potential function of these weapons, though, seems doubtful. When one group of baboons in Namibia dislodged stones from a cliff when they were disturbed by humans, they did so not only when people were under the cliff but also when they were too far away to be struck. At Gombe, where chimpanzees compete with baboons for food, chimpanzees throw branches at baboons. Baboons however, never throw objects at chimpanzees.

Chimpanzees and orangutans are different. In captivity these animals, which are apes rather than monkeys, attend closely to a demonstrator when learning to use tools to open boxes, and they require very few trials to learn to copy his actions. They seem to recognize the intentions and goals of the demonstrator, and they rapidly learn a tool’s function from attending to his behavior. Although they do not copy the demonstrator’s exact motor patterns as closely as children do, they do tend to conform to his technique.

Under natural conditions, chimpanzees and orangutans also use a variety of tools for different purposes. In fact, different populations of chimpanzees and orangutans use different kinds of tools for different purposes, and the use of specific tool types appears to be socially transmitted. Two points about tool use in chimpanzees and orangutans seem relevant. First, in marked contrast to monkeys, no population of chimpanzees has been reported not to use tools. Second, unlike monkeys, chimpanzees and orangutans often show foresight and planning in selecting and modifying tools in advance of their use. Before fishing for termites, chimpanzees often search some distance from the termite mound to find an appropriate prodding stick and strip the bark from it. Similarly, when preparing to crack open nuts, chimpanzees must carry both stones and nuts to suitable hard surfaces. Often, this means that a chimpanzee will carry both nuts and stones over considerable distances before beginning a nut-cracking session.

In their ability to plan, understand a tool’s function, and appreciate a demonstrator’s goals, then, apes are strikingly different from most monkeys. This is not to say, however, that tool use and manufacture are unique to apes, or that monkeys are completely incapable of imitation.?

1.Almost all animals learn novel tasks more easily if they can observe a knowledgeable demonstrator Biologist Tom Langen trained individual magpie jays to pry open a door on box that contained food. Subsequently, birds whose social groups included a demonstrator learned how to open doors much more rapidly than birds whose groups did not Indeed, birds in groups that lacked a demonstrator did not even realize that there was food in the boxes Similarly, in captivity, many monkeys can learn to use?rudimentary?tools to obtain food, and they do so more quickly and accurately in the presence of a demonstrator. If monkeys learned like humans do. it would be safe to assume that the monkeys learn to perform the tasks by watching the demonstrator and imitating his actions. This would imply that the monkeys understand the demonstrator’s intentions and goals. But this does not seem to be the case.

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