Washington, August 29 : Experts at Great Ape Trust of Iowa have opened an important new chapter in a decades-long debate about the linguistic capabilities of apes, by applying linguistic tools used to analyse human language to a conversation between a language-competent bonobo and a scientist.
Janni Pedersen, an Iowa State University Ph.D. candidate from Denmark, and William M. Fields, director of bonobo research at Great Ape Trust, say that their study indicates the bonobos may exhibit larger linguistic competency in ordinary conversation than in controlled experimental settings.
Writing about their study in the Journal of Integrative Psychological and Behavioral Science, the researchers say that their findings run counter to the view among some linguists who argue that only humans possess and use language.
Some scientists believe that language is part of the genetic makeup of humans, which did not descend from a single primitive language evolved from the lower primate order, and it must include formal structures such as grammar and syntax.
"The resistance to this in the scientific community is enormous. For the first time, we have a student who is using linguistic tools that have normally been applied to humans now being applied to non-humans. This is a move toward using the kinds of methodology that are appropriate in ape language, based on Savage-Rumbaugh's 1993 monograph, Language Comprehension in Ape and Child," Fields said.
For her research paper, Pedersen analysed a videotaped conversation between the bonobo Panbanisha and Dr. Sue Savage-Rumbaugh, now a scientist with special standing at Great Ape Trust.
In the video, Panbanisha was in the forest with Savage-Rumbaugh and an assistant, who had a dog in tow that the bonobo did not like.
Though Panbanisha and Savage-Rumbaugh moved from topic to topic in the conversation, Panbanisha repeatedly used the lexigrams to express her desire to be carried by the assistant, who was tending to the dog.
The bonobo remained firm despite being offered other resolutions by Savage-Rumbaugh, and finally the ape prevailed and was carried from the forest by the assistant.
Pedersen said that linguistic aspects of the conversation included turn taking, negotiation, pauses and repetition, and went far beyond information sharing made possible through the use of lexigrams symbols.
"She was using language to get at what she wanted. She is very, very clever and is fully capable of following the conversation the same way a human does. This tells me that Panbanisha's knowledge of language is far beyond understanding the words, to understanding how to use them in a conversation to get what she wants," Pedersen said.
Fields added: "The importance of Janni's Ph.D. can't be overstated," Fields said. "Hers will be the first Ph.D. produced in ape language since the research moved to Iowa."
He further said: "Janni is an important part of the future, and she will help carry ape language research further."