The groundbreaking primate study of Kanzi, a bonobo who mastered over 300 symbols and understood spoken English, comes to an end with his passing. As the ape-language research era draws to a close, scientists reflect on what decades of experiments have taught us — and at what cost.
A ‘talking’ ape’s death signals the end of an era
Kanzi is a bonobo who has been studied for his exceptional cognitive abilities.
Born in 1980 at the Lola ya Bonobo Sanctuary in the Democratic Republic of Congo, Kanzi was taught to communicate using lexigrams, symbols that represent words or sounds.
He quickly learned over 450 vocabulary items and demonstrated an understanding of 'grammar' and 'syntax'.
Kanzi's language skills are comparable to those of a human child aged 2-3 years old.
His cognitive abilities have been extensively studied, providing valuable insights into the evolution of 'language' and 'intelligence'.
The passing of Kanzi, a bonobo who mastered more than 300 symbols and understood spoken English, marks the end of an era in ape-language research. “It’s a reminder that supporting science journalism is more important than ever, as it empowers people to evaluate the news and the world around them.” Kanzi’s death offers an opportunity to reflect on what decades of experiments have taught us — and at what cost.
A History of Ape-Language Experiments
Language – communication marked by using symbols, grammar, and syntax – has long been considered among the abilities that make humans unique. When it comes to delineating the exact boundary separating us from other animals, scientists often turn to our closest living relatives, the great apes.
In the 1940s, psychologists tried raising a baby chimp named Viki at home as a human. After seven years of speaking lessons, she could utter only four words: mama, papa, cup, and up. Eventually, scientists determined that chimpanzee anatomy doesn’t allow for speech, although some recent research questions this conclusion.
In the 1960s, researchers took a different approach, one suggested as early as the 17th century: Teach apes sign language. One famous case involved psychologists Allen and Beatrix Gardner bringing Washoe – a wild chimp who had been captured in Africa for NASA but never became a chimponaut – to the University of Nevada, Reno. Researchers shaped Washoe‘s hands to teach her signs, and she came to use over 100 of them by age 4.
Ape language studies involve analyzing the vocalizations, gestures, and signs used by primates to communicate.
Researchers have identified distinct patterns in ape language, including a vocabulary of over 1,000 signs used by chimpanzees.
Gorillas have been taught human sign language, with some individuals learning hundreds of words.
Studies suggest that apes possess cognitive abilities similar to those of humans, enabling them to comprehend and use language.
Observations of ape behavior provide valuable insights into the evolution of language and its relationship to intelligence.
The study with Kanzi was different. His adoptive mother, Sue Savage-Rumbaugh, taught him a system of visual symbols that each represented a word or phrase. These “lexigrams” were abstract and thus not a clue to what the symbol meant. However, Kanzi absorbed this language the way a human infant does.
Kanzi‘s work showed that our simian relatives do have some capacity for language, causing scientists to rethink human uniqueness. His conversations may have been more transactional than humans’, with an imperative usage of “want[ing] things.” Still, these experiments demonstrated that apes have complex interior lives and the ability to express them directly.
Ape-language research focuses on deciphering and understanding non-human primate communication.
Studies have shown that apes, such as chimpanzees and bonobos, possess complex vocalizations and sign languages.
Researchers have identified over 100 distinct vocalizations in chimpanzees, including 'alarm calls' and social greetings.
In captivity, some apes have learned human sign language, with notable examples including 'Washoe' and 'Koko'.
These findings challenge the notion of a strict species barrier between humans and non-human primates.
But that recognition may have doomed ape-language studies. In recent decades, scientists have questioned whether it’s ethical to conduct experiments on intelligent, highly social creatures. What happens when a study ends or loses funding? What happens if the ape is no longer around familiar faces or has no one to “talk” to?
Studying Apes and Language Today
Today, researchers focus on studying natural ape communication. For example, scientists have compiled a “lexicon” of bonobo calls, discovering that apes combine calls in complex ways. This may be a stretch to call true syntax, but it’s another linguistic feat once thought to be unique to humans.
The end of Kanzi‘s life signals the end of an era in ape-language research. It’s a reminder that supporting science journalism is more important than ever, as it empowers people to evaluate the news and the world around them.
- sciencenews.org | A ‘talking’ ape’s death signals the end of an era
