SIGN LANGUAGE AND COMPARATIVE COGNITION
Research around forms of communication beyond human language
has produced important information about animal communication. In this sense,
there are two linguistic laws that have been observed in species other than the
human species. One of them is an indirect relationship between the length of
words and the frequency of their use. This law has been observed in the
communication, both oral and gestural, of different animals, in addition to the
human being. On the other hand, there is another law which is based on the fact
that the longest communication sequences are formed from shorter elements. After
observing a group of chimpanzees, a team of researchers has been able to derive
the first evidence that these laws are fulfilled in the gestural communication
of these animals.
In addition to using gestures with their limbs, chimpanzees
communicate with noises, facial gestures, and body postures. In this regard, according
to the researchers, the gestures used by chimpanzees to communicate follow the
same rules associated with human language.
Washoe, a chimpanzee born in the wild in West Africa in
1965, is the subject of an investigation at the University of Nevada, which
aimed to teach Washoe American Sign Language. Washoe learned to identify
sadness and express it in sign language, she knew how to lie or even apologize.
The most surprising thing is that she transmitted American Sign Language from
generation to generation: Washoe's son died a few days after birth, but they
found an orphaned chimpanzee calf which she received with love.
In addition, the scientists also observed that, after
learning sign language, other chimpanzees managed to have conversations with
each other in that language. Washoe and sign language totally changed the way
of understanding communication and even respect for the animal world.