Did you too dreamed to be like Dr. Doolittle and talk with animals? What would that language be like? Then, this blog is for you!
Communication in the animal kingdom takes on many on many shapes and forms, and is often highly sophisticated. For example, whales from different regions communicate using series of clicks that differ in dialect1, just like people born in North Italy speak a different dialect from the one in the South. Male frogs use a variety of different calls to attract females or deter competing males2. Dolphins identify themselves by using a
“signature whistle”3, which is different for each member of the group. In some Songbird species, the young birds learn their species-typical song from their parents4.
How chimpanzees speak
Language research is divided into language comprehension and production. Understanding what others “say” is different from being able to “speak”. After attempts to teach chimpanzees the use of vocal language, research shifted into using American Sign Language and lexigrams (sets of icons that symbolize objects and ideas).
Washoe- the speaking ape
The most famous language trained ape was Washoe, a female chimpanzee, that according to her caretakers and trainers, Allen and Beatrix Gardner, was able to sign over 350 different words.
The Gardeners claimed that Washoe conducted sentences and combined words to create new meanings5, for example signing the combination “water” and “bird” when referring to a duck. However, critiques pointed out many conceptual and methodological problems in the Gardeners research6.
Was Washoe really using signs or just ringing bells?
The first critique was that the simple use of a sign does not necessarily reflect the use of language. Animals trained with operant conditioning learn to operate a device or display certain behaviors in order to receive a reward. From this point of view, the cognitive process Washoe performed did not necessarily differ from those of a cat ringing a bell for food or a dog pushing a button to go out.
Was she using sentences?
The gardeners claimed the way in which Washoe Composed sentences, was similar to that of children. However, when children learn to speak, they typically use simplified versions of adult sentences, like “give banana”. Unlike children, sentences produced by Washoe, and other language trained apes, had a characteristic form of repetition. For example, the ape might sign “you me banana me banana you”6. Remember the cat that was taught to press a bell? Typically, if you would not feed it, the cat would repeatedly press the bell in frustration.
Further more, the Gardeners were criticized for not providing comprehensive data to support their claims that Washoe was at all conducting meaningful sentences. They should have not provided data only for those times in which Washoe was apparently composing meaningful sentences, but rather for all the occasions in which she used the signs. Otherwise, it may be the case that she was just randomly using signs, and by chance sometimes this happened to make sense in the eyes of the human observer6.
How about other “speaking” apes?
Other studies that used different ways to teach symbols as a form of language7, received similar critiques. Mostly that the data they presented was not sufficient to back up their claims, and that the researchers may have been biased when interpreting the results.
A famous chimpanzee and a famous linguist
One study tried to use the same methods used for teaching Washoe, with a chimpanzee called Nim Chimpsky8. Nim was humorously named after Noam Chomsky, a renowned linguist, that claimed apes are incapable of using language. It is perhaps slightly ironic that the researchers working with Nim were unable to replicate Washoe’s results. They concluded that Nim did not show evidence of using American Sign Language.
What does it take to prove an animal is using symbols similarly to the way humans use words?
There are many requirements to prove that an animal is using language. The basic requirements for proving that an ape is using symbols in a meaningful way are:
- It must be able to name objects consistently in different situations (e.g. recognize that boots are shoes, but also snickers, regardless of the situation or environment).
- It must be able to identify a specific property in a new object (e.g. the cup is blue).
- It should identify multiple properties in a single object (the cup is blue but also big).
- Use signs without being prompted and without receiving immediate feedback.
- Spontaneously produce signs without a clear reward.
- Identify relations between objects (such as the cup is on top of the table).
Can animals use human language?
As such evidence is lacking, today there is a consensus among researchers that apes are not able to use human language. The critical points of view mentioned above should be kept in mind in all studies related to language trained animals. This includes the recently popular videos of dogs that can supposedly communicate complex messages by pressing buttons. However, there is no doubt that the natural way in which dogs communicate with their owners is astonishing.
If we really want to be like Dr. Doolittle, perhaps we should focus more on understanding the calls of frogs and the accents of whales, instead of trying to capture other animals in the limits of our own language.
1Weilgart, L., Whitehead, H., 1997. Group-specific dialects and geographical variation in coda repertoire in South Pacific sperm whales. Behav. Ecol. Sociobiol. 40, 277–285. https://doi.org/10.1007/s002650050343
2Kelley, D.B., 2004. Vocal communication in frogs. Curr. Opin. Neurobiol. 14, 751–757. https://doi.org/10.1016/j.conb.2004.10.015
3Harley, H.E., 2008. Whistle discrimination and categorization by the Atlantic bottlenose dolphin (Tursiops truncatus): A review of the signature whistle framework and a perceptual test. Behav. Processes 77, 243–268. https://doi.org/10.1016/j.beproc.2007.11.002
4Slater, P.J.B., 1986. The cultural transmission of bird song. Trends Ecol. Evol. 1, 94–97. Https://doi.org/10.1016/0169-5347(86)90032-7
5Gardner, R.A., Gardner, B.T., Gardner, R.A., Gardner, B.T., 1969. Teaching Sign Language to a Chimpanzee Linked references are available on JSTOR for this article : Teaching Sign Language to a Chimpanzee A standardized system of gestures provides a means. Sci. New Ser. 165, 664–672.
6Seidenberg, M.S., Petitto, L.A., 1979. Signing behavior in apes: A vritical review. Cognition 7, 177–215. https://doi.org/10.1016/0010-0277(79)90019-2
7Patterson, F (1978) The gestures of a gorilla: Language acquisiton in another pongid. Brain Lang. 5, 56-71
8Terrace, HS., Petitto, LA., Sanders, RJ., Bever TG., (1979) can an ape create a sentence? Science, 206, 4421, 891-902. DOI: 10.1126/science.504995