Bonobos, great apes closely related to chimpanzees, have demonstrated an ability to engage in pretend play, suggesting that imagination – once considered uniquely human – may be more widespread in the animal kingdom. New research published in Science shows that Kanzi, a bonobo who communicated using lexigrams (symbols representing words), consistently identified imaginary juice and grapes during a pretend tea party experiment. This finding challenges long-held assumptions about cognitive abilities in non-human primates and raises questions about the evolutionary origins of imagination.
The Experiment and Its Implications
Researchers Amalia Bastos and Christopher Krupenye designed a series of tests to determine if Kanzi could track make-believe objects. During one experiment, the researchers pretended to pour imaginary juice into glasses, then asked Kanzi to identify which glass remained full. Kanzi correctly selected the glass with the imaginary juice more than two-thirds of the time, far exceeding chance. To rule out visual impairment, the team also presented Kanzi with real and fake juice, confirming his ability to distinguish between them. He consistently chose the cup with real juice nearly 80% of the time, proving he was consciously participating in the pretense.
This behavior is significant because imagination is a foundational skill in human cognition. It underpins tool use, problem-solving, and even social understanding. If imagination is present in other primates, it suggests that the capacity for complex thought may have evolved earlier than previously believed.
Why This Matters: Beyond Human Exceptionalism
For decades, scientists believed that only humans possessed the ability to mentally represent things that don’t physically exist. The bonobo’s performance suggests this may not be true. Imagination isn’t merely a byproduct of advanced intelligence; it may be a more primitive cognitive function.
The study also highlights the importance of communication. Kanzi learned to use lexigrams, allowing him to participate in experiments that tested his understanding of abstract concepts. This raises the question of whether other apes, even those not raised in human-controlled environments, could also demonstrate imagination if given the means to express it.
The Legacy of Kanzi and Future Research
Kanzi passed away in March 2025, leaving behind a legacy as one of the last apes raised in an attempt to bridge the communication gap between humans and primates. Today, researchers are shifting their focus to studying animal communication in natural settings. Bastos now plans to expand the study to include bonobos who haven’t had extensive human contact, seeking to determine whether pretend play is an innate ability or a learned behavior.
“If other animals also have imagination, they could be doing the same [inventing tools and concepts]… You can’t invent a bicycle if you can’t imagine one first.” — Cathal O’Madagain, cognitive scientist.
Ultimately, the bonobo’s imaginary tea party serves as a compelling reminder that intelligence and imagination are not exclusive to humans, but rather part of a broader spectrum of cognitive abilities shared across the animal kingdom.
