Lock identified two steps to learning language
- Associative symbol learning - A child learns to associate specific sounds with specific objects.
- Representational symbol learning - Using sounds to refer to the objects (i.e responding to 'get your ball' when the ball is in another room)
Pygmy chimps are a more social species than other apes and display highly developed social skills
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- To study human language capabilities in pygmy chimps.
- It should be possible to demonstrate human language capabilities by needing no training and being able to provide different responses on cue.
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Procedure, Method and Sample
- Principal subject was a pygmy chimpanzee called Kanzi aged 30-47 months.
- A second Chimpanzee was studied, Kanzi's younger sister, Mulika aged 11-21 months.
- Both spent several hours a day with their mother but appeared to prefer human company.
- Two common chimps were included as comparisions - Austin and Sherman.
- Kanzi and Mulika used lexigrams which brightened when touched. They were on an electric keyboard or a pointing board, and a speech synthesiser was added so that appropriate words were spoken when a symbol was touched.
- K was exposed to the use of symbols, gestures and human speech from the age of 6 months as he watched the interactions between Matata (his mother) and the keepers, there was no attempt to train Kanzi directly.
- From the age of 1+1/2 K began to show an interest in the symbols, and began to learn an association between touching symbols and food dispension, but he didn't show an understanding of specific symbols being associated with specific food. He spontaneously started to use the chase lexigram to initiate a game of chase, and also started to use hand clapping for the same purpose.
- Kanzi was seperated from his mother at the age of 2+1/2 years so that Matata could take part in a breeding programme. When she returned, Kanzi had developed a preference for human company. Mulika was born 9 months later and Kanzi enjoyed spending time with her. Mulika developed an eye infection and was seperated for treatment. When she returned she also chose to stay with her human companions most of the time. Mulika observed Kanzi using lexigrams, but not her mother.
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Procedure, Method and Sample 2
- Sherman and Austin were trained to use lexigrams.
- During the warmer months, food was placed at 17 named locations within the forest. The name matched the food that was found there.
- At first, Kanzi was shown pictures of various foods and asked which one he wanted to eat, and was then taken there. Within four months, Kanzi could select a photo and guide others to the right place, sometimes carrying Mulika. Later he could use the symbols alone and Mulika began to use the symbols to initiatite travel.
- When the chimps used lexigrams indoors it was automatically recorded by a computer. Outdoors, the record was made by hand and entered into the computer at the end of each day which meant there were a complete record of utterances.
- Each utterence was correct/incorrect, spontaneous/imitated/structured.
- In order to count a word as being 'acquired' it had to be a spontaneous utterance which could be verified 9/10 times.
- 4+1/2 hour of observations made in real time were compared with a video tape of the same period of time. There was 100% agreement on lexigram use, but the video-tape watcher recorded an extra nine utterances and disagreed over whether one was spontaneous of not.
- Kanzi and Mulika were formally tested on all the words in their vocabulary, this was by being shown photographs and picking the right lexigram, listening to a word and asked to select the right photo or lexigram.
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- Kanzi and Mulika naturally used gestures to communicate, and tended to be more explicit than those of Austin and Sherman.
- Kanzi immediately had a fair vocabulary when he started to use the lexigram, Mulika began using the lexigrams earlier than Kanzi, but began using particular symbols for all purpose of things. She did learn to use a number of lexigrams appropriately, but occasionally reverted to using 'milk' as an all purpose communication.
- Both chimps started using a new term in an associative context first. (Kanzi first heard the word Strawberries' at the mushroom site, and then went to the strawberry site to taste some. Initially, Kanzi's spontaneous use of strawberries was restricted to the mushroom site) but eventually extended to context-free situations
- Kanzi acquired 46 words, and Mulika 37.
- Kanzi's multisymbol expressions appeared within one month of of lexigram usage, but was far fewer than single symbol utterances..
- Kanzi and Mulika imitated most often when learning new words. 15% of utterances were imitation and 80% were spontaneous which is similar to a human child.
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- Sherman and Austin were initially confused by the formal tests as they anticipated that they would get the object when they identified it. Kanzi and Mulika did well from the start, although had a little difficulty when the word was produced by a synthesiser - although the experimenters also found this hard to understand.
- A 'blind' test was arranged with somebody who had never been in the woods before. Kanzi was able to choose a symbol or photograph and go to the correct place. He did however take a route which he was not normally allowed to take. There were two areas not selected by Kanzi, and when the visitor used spoken English to ask him to guide him there Kanzi was able to do so.
- Both Kanzi and Mulika made generalisations beyond the particular meaning of the word. (e.g. using tomato for round red fruits.)
- Kanzi also used words in different ways. If he said 'juice; and then went to that area, and didnt look for juice, its possible he was referring to the area and not the drink.
- Sometimes Kanzi would take the lexigram and went off by himself to use it, he could also use the 'no play' symbol.
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Case Study/Observational Study
- Longitudinal and indepth study of a small amount of participants over a period of time to measure differences in the individual.
- Observed by researchers and used computerised lexigrams to record information.
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- Amount of gestures
- Lexigram use
- Acquisition of words
- Combinations of words
- Imitation frequency
- Formal tests
- Blind test
- Generalisations made by the chimps.
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- Species of Chimp
- Age of Chimp
- Whether the chimp was trained to use the lexigram
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- Small sample - unreasonable to make generalisations
- Kanzi and Mulika acquired language easier than Sherman and Austin. Matata did not acquire symbols spontaneously and required the most training so there may be a 'critical age' for learning.
- Nobody ever tried to teach them to respond to English commands. They understood the word and then just had to link it to the correct symbol. This suggests that the way pygmy chimps acquire graphic symbols is fundamentally different from common chimps.
- It appears that pygmy chimps have a propensity for the acquisition of symbols.
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- Chimps raised in captivity
- Odd seperations from mother
- Preferred human contact
- S+A trained.
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- Chimps in captivity
- Is it right to teach human language to animals?
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