Language Learning in Bonobos and Chimpanzees
Comparing Kanzi's Linguistic Abilities to those of other Great Apes
Feb 28, 2009
Kanzi is a male bonobo who was brought to the Georgia State University Language Research Centre with his mother when he was 6 months old. He is a male bonobo and the first non-human animal to have learned language without explicit training, just like a human child does.
Kanzi surpassed the other chimpanzees who had been trained at the research centre. He learned more language symbols and was able to produce more items and combinations. He was also able to comprehend spoken speech and did not have to be explicitly trained, unlike any of the other apes.
How does Kanzi’s achievement compare to that of the chimpanzees who learned sign language? This question is answered here by comparing Kanzi’s language skills to those of Nim Chimpsky and Washoe.
Kanzi Compared to Nim Chimpsky
Major differences between Nim and Kanzi are that Nim seemed to imitate his trainers, his strings of signs did not add anymore meaning to utterance than single signs, he interrupted conversations instead of taking turns, and, crucially, he signed when he could get a reward.
Overall, Kanzi provides more information with his longer utterances, while Nim did not. Kanzi does not repeat a word in a given combination; he typically indicates who is to be the agent and who the patient by touching. Roughly a third of Kanzi’s utterances specify someone else as the beneficiary of the action, while none of Nim’s did. Two-thirds of Nim’s utterances were food requests, while none of Kanzi’s were (Rumbaugh 1986, p.393).
Kanzi Compared to Washoe
Washoe had more success than Nim in learning language. She was taught American Sign Language by being shown an object after which the trainer would mold her hands into the appropriate formation. No one was permitted to speak in her presence, only signing was allowed. Her researchers treated her like humans treat children, by modeling the language for them.
Like Kanzi, Washoe would sign to herself and with other chimps, and she learned signs from other chimps. As well, Washoe had a foster son who was not trained by humans, but he did learn more than 50 signs from Washoe and the other chimpanzees. Washoe was able to generalize her signs to objects other than the specific ones she was taught and she was able to combine signs (ibid., 18-21).
Unlike Kanzi, however, Washoe did not display comprehension of what was being signed to her. As well, she expressed her needs better than she understood or complied with those of others. Like Nim, she used a lot of meaningless repetition and she did not learn signs unless they were taught to her.
In summary, unlike Nim, Washoe, and the other chimpanzees, Kanzi:
- learned language without being explicitly trained,
- used it to initiate conversations in the absence of rewards,
- spoke about other people and chimpanzees,
- was able to comprehend spoken speech,
- did not produce strings of words with meaningless repetition.
References
Rumbaugh, S.R. (1986). Ape Language: From Conditioned Response to Symbol. New York: Columbia University Press.
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