Bonobo Passes ‘Imaginary Juice’ Test, Challenging Human Uniqueness
- The line between human and animal cognition continues to blur with new research suggesting bonobos possess a capacity for imagination previously thought unique to humans.
- Researchers presented Kanzi with a scenario involving “juice,” a favorite treat.
- Amalia Bastos, a comparative psychologist at the University of St Andrews in Scotland, who first met Kanzi in 2023, described the experience as “starstruck.” She recounted how Kanzi,...
The line between human and animal cognition continues to blur with new research suggesting bonobos possess a capacity for imagination previously thought unique to humans. A study published February 5 in Science details how Kanzi, a bonobo who gained renown for his ability to communicate using lexigrams, demonstrated an understanding of pretense – the ability to track things that aren’t actually there.
Researchers presented Kanzi with a scenario involving “juice,” a favorite treat. An experimenter pretended to pour juice into two glasses from an empty pitcher, then pretended to pour the contents of one glass back into the pitcher. When asked which glass still contained the “juice,” Kanzi correctly identified the empty glass 68% of the time, a statistically significant result. This suggests he wasn’t simply reacting to visual cues, but rather tracking an invisible quantity.
Amalia Bastos, a comparative psychologist at the University of St Andrews in Scotland, who first met Kanzi in , described the experience as “starstruck.” She recounted how Kanzi, using his lexigram board, initiated a request for her and a colleague to chase each other, and appeared to enjoy watching their pretend play. This observation sparked the series of tests designed to explore Kanzi’s cognitive abilities.
However, the researchers acknowledged the need for caution in interpreting the results. Bastos noted the possibility that Kanzi’s success wasn’t necessarily due to imagination, but rather to other factors. “Kanzi is an old bonobo. Maybe his vision isn’t very good. Maybe he thinks that there’s real juice in these things,” she explained.
To address this concern, the researchers conducted further testing. They presented Kanzi with two cups – one containing actual orange juice and the other filled with a pretend juice. Kanzi correctly chose the cup with real juice nearly of the time, indicating he could reliably distinguish between reality and pretense. A subsequent test, mirroring the first but using pretend grapes instead of juice, yielded similar results, further supporting the idea that Kanzi understood the location of the imaginary food.
This ability to understand and respond to pretense has significant implications for our understanding of animal cognition. Cathal O’Madagain, a cognitive scientist at the University of Mohammad VI Polytechnic in Morocco, who was not involved in the study, highlighted the link between imagination and innovation. “You can’t invent a bicycle if you can’t imagine one first,” he said. He suggested that if animals possess a similar capacity for imagination, it could reshape our understanding of their tool use and problem-solving abilities.
The study builds on decades of research into Kanzi’s remarkable cognitive abilities. He learned to communicate using lexigrams – symbols representing words or concepts – and demonstrated an aptitude for understanding spoken language. He also exhibited the ability to create stone tools, and even played the video game Minecraft, showcasing a level of cognitive flexibility rarely observed in non-human primates.
Kanzi passed away in , making him one of the last animals raised in a human environment from birth. Bastos plans to continue this line of research by investigating whether other apes, without Kanzi’s unique upbringing and training, can also demonstrate an understanding of pretense. This will help determine whether Kanzi’s abilities were a result of his specific circumstances or a more widespread cognitive capacity within the ape family.
The findings add to a growing body of evidence suggesting that the cognitive boundaries between humans and other animals may not be as distinct as previously believed. While further research is needed to fully understand the extent of animal imagination, Kanzi’s story offers a compelling glimpse into the complex inner lives of our primate relatives.
Research also suggests bonobos possess strong social cognition skills. A Facebook post highlighted research indicating that chimpanzees and bonobos demonstrate a remarkable ability to remember faces, challenging the notion that long-term social memory is exclusive to humans. Studies, including one published in in PNAS, suggest that great apes can anticipate the actions of others based on their own experiences, indicating a level of understanding of intention and perspective.
The ability to understand non-adjacent dependencies – a key component of complex language processing – is also being investigated in bonobos, as detailed in research published in . While the extent of their capacity in this area is still under investigation, these studies contribute to a broader understanding of the cognitive abilities of these intelligent primates.