Experiment Module: Attempts To Teach
Language to Primates Over the centuries, theologians, philosophers,
and even biologists have claimed that language did not exist in any animals besides
humans. But the data that have now been gathered on the sophisticated communication
methods used by animals as diverse as bees, birds, whales, and the great apes
now make it impossible to support this position in the broadest sense. Chimpanzees
in their natural habitat display social communication that is quite elaborate,
based on gestures, manipulations of objects, and facial expressions. They also
have a natural system of vocalization that seems to include certain referential
components, such as cries of alarm to inform the other members of their group
of a particular kind of danger. Despite all this, communication in the
great apes is really quite different from human communication, for two main reasons:
communication among the great apes is essentially affective (whereas human language
is cognitive and referential) and is controlled by subcortical structures (whereas
human language is essentially cortical). Human language still appears to
be unique from a semantic standpoint, that is, in its ability to associate particular
meanings with arbitrary symbols. But because these human language abilities must
have evolved from abilities present in our primate ancestors, many researchers
have believed that it might be possible for primates to learn human language. One
outstanding finding from the research to date: despite repeated attempts since
the 1940s to rear juvenile chimpanzees like children, they have never managed
to speak, because their larynxes do not let them produce the sounds of human language.
The chimps do, however, seem able to learn a few rudiments of symbolic communication
if they are given the chance to use symbols mounted on pieces of plastic, or some
elements of sign language, or a computer screen with a symbol keyboard. With a
symbol keyboard and adequate training, some chimpanzees have learned to choose
among over 400 symbols to construct expressions and hold rudimentary conversations
with their teachers. Researchers have even claimed that their most talented animals
managed to master a vocabulary of a few thousand words, the equivalent of the
language abilities of a human child 3 to 4 years old. The bonobo monkey
Kanzi regularly used 250 lexigrams (symbols, each representing a single word)
from a selection of 500. Dolphins also can communicate concepts to one another.
If a group of dolphins learns a task, and then a new dolphin is placed in their
tank, they can explain the task to him or her. They can also distinguish between
reality and representations of reality (such as on a television screen).
Two of the most famous primates to have learned the meanings of sign-language
gestures were Washoe—a chimpanzee reared by American psychologists R. Allen
and Beatrice Gardner and studied by their colleague, Roger Fouts—and Koko,
a gorilla trained by American psychologist Francine Patterson. But beyond showing
that these primates may have had good memories, their rudimentary use of sign
language gives no clear information about their ability to produce various combinations
of symbols according to rules of grammar to express new things. The question
of animals’ use of language therefore remains controversial and gives rise
to varying interpretations of certain observations. For example, in one case,
a chimpanzee who had learned the sign for “water” and the sign for
“bird” and then saw a swan swimming used the two signs together, supposedly
to signify “water bird”. But scientists who do not believe in animal
language argue that the chimpanzee may very well have been making two separate
signs, one to designate the water and the other to designate the bird. They add
that chimps who have been trained in sign language often use other symbol combinations
that are illogical or unintelligible. Hence it is hard to say whether an association
such as “water bird” reflects a flash of lucid language in chimpanzees
or whether it is simply a set of coincidences observed by researchers who believe
that chimpanzees are capable of a certain amount of language. In any case,
the least we can say is that any assertions about language in animals should be
approached with extreme caution. The vocalizations used by our close relatives,
the chimpanzees, to assert their dominance or to warn their group about threats
are highly limited and are used in highly stereotyped situations, compared with
human language. Thus no evidence currently exists to back the claim that communication
in monkeys or dolphins approaches human language, with its nearly infinite possibilities
for associating symbols to produce meanings. One caveat, however: the ability
to use language is not a prerequisite for the ability to think. Monkeys, like
humans who are raised in isolation and never learn language, can still accomplish
many things that require abstract reasoning. Many of the greatest creative minds
in human history have reported that they got their best ideas from a kind of thinking
that did not involve language. Albert Einstein, for example, said that he got
many of his ideas about relativity by imagining himself riding horseback on a
ray of light and looking around him at clocks and other objects as he did so.
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