Savage Rumbaugh

AIMS: 

• study language aquisition of two pygmy chimpanzees - Kanzi and Mulika compared to 2 common chimps, Austin and Sherman

METHOD:

• Case Study - 17 months

PARTICIPANTS:

• Kanzi - male bonobo (abandoned by birth mother) - 2yrs6months
• Mulika - female bonobo (mother Matata also brought up Kanzi) - 11months
• both were exposed to language from a young age through their mother - looked after by humans
• Austin and Sherman - male common chimps, 5/6 years old

PROCEDURE:

• taught language using lexigram (inside attached to computer, outside used a laminated board and recorded results) - linked to voice synthesizer - as bonobos are unable to produce human like vocalisations (voicebox located lower down that humans)
• intially only 8 lexigram symbols -> 256 at end of study
• also taught american sign language
• ALL FOUR PRIMATES taught by the SAME instructor in similar atmosphere
• Kanzi/Mulika did most learning by observation whereas Austin/Sherman needed rewards
• Coding: Correct, Incorrect, Imitated, Structured, 
• used real time recordings and visual recordings
• For word to be in vocab: behavioural concordance (symbol matched behaviour) and 9/10 used spontaneously, observers compared data (IRR)
• Daily formal tests: asked to find appropriate symbols on lexigram, (blind test)

RESULTS:

• Over study Kanzi acquired 45 words e.g. Orange, Banana and Mulika 37 e.g. Milk, Egg
• Mulika was initially slower at acquiring words
• Kanzi Developed spontaneous gestures e.g. taking a nut and banging hand - asking to be opened, started making combinations 
• Over 17 months Kanzi produced 2805…