To investigate spontaneous language acquisition in pygmy chimps (bonobos) compared to that of normal chimps and to see whether language can truly be used by them.

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  • Quasi experiment (the IV was naturally occuring) - species of chimps
  • Case study as it focused on Kanzi
  • Data was gatehred by observation
  • Longitudinal study over a 17 month period
  • involved observation as blind experiments coded as whether or not language was spontaneous and being used or mimicked.
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  • 2 pygmy chimps (bonobos)
  1. Kanzi 
  2. Mulika
  • Both were not children of Mutata who was trained to be a language monkey. Mutata kidnapped them from Lorel.
  • 2 common chimps
  1. Sherman 
  2. Austin
  • Pushed to one side in this experiment as it was evident that they couldn't use or understand English.
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Chimps were kept in a naturalisitc outdoor environment and an indoor reasearch centre.

The forest was 55 acres with 17 food places around the forest. Kanxi communicated about food in a forest in a backpack with lexigrams.

To communicate the experimentor used lexigrams as a visual that the chimps could point at to reply. They also had a voice synthesiser that was connected to a keyboard of symbols. They weren't trained, they learn't how to do these things from watching other people and their mother, mutata. 

Sherman and Austin were trained and were not able to understand the synsthesiser.

Data was recored via blind experimenters who Kanzi was told to take to various places. There was also real time and recorded videop tapes. - researchers coded these to see if there was any spontaneous language.

There was also formal tests at the end which involved testing all the words of their vocabulary whilst avoiding cues. They were also asked to correctly match lexigrams to photographs to prove they knew what they were.

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  • 6-16 months Kanzi and Mulika spontaneously began to use gestures to communicate. They could spontaneously use lexigrams by the two videos recordings and the chimps were correct most of the time.
  • Mulika and Kanzi gestures were often more explicit than Sherman and Austin
  • Sherman and Austin believed that labelling objects in the formal tests correctly would then main that they would gain the item.
  • Kanzi and Mulika comprehended lexigrams muche easier
  • Kanzi and Mulika were able to comprehand English speking words
  • Kanzi and Mulika used lexigrams more specifically eg.g Coke compared to drink
  • Kanzi could refer to others (you chase him). Austin and Sherman could only refer to themselves.
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  • Many controls and formal tests to increase validity and reliability
  • A lot of anecdotal evidence gatherd in some studies.
  • It acquires both qualitative and quantitative data


  • Ethical issues- humanising chimps, diet may harm, frustration of chimps.
  • The sample was very small anfd far too expensive.
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