The bonobo’s remarkable performance in pretend play experiments highlights its mental capability to envision non-existent objects, a trait that may stretch back 6 to 9 million years, challenging previous beliefs about the uniqueness of human imagination.
“The realization that their cognitive experiences extend beyond the immediate present is revolutionary,” remarked Dr. Christopher Krupenier, a researcher at Johns Hopkins University.
“Imagination, once thought to be an exclusive human trait, is now being reconsidered as something that may not solely belong to our species.”
“Jane Goodall’s discovery of tool-making in chimpanzees altered our understanding of what it means to be human, prompting a reevaluation of the unique qualities of mental life across different species.”
By the age of two, human children engage in pretend play, like tea parties.
Even infants as young as 15 months display surprise when witnessing someone “drinking” from a cup filled with imaginary content.
While there have been anecdotal observations of animals showcasing pretend behavior in both wild and captive settings, controlled studies on pretend play in non-human animals remain scarce.
For instance, young female chimpanzees have been seen playing with sticks, mirroring how a mother would cradle an infant.
Captive chimpanzees have even been noted dragging imaginary blocks along the ground after interacting with real wooden blocks.
Dr. Krupenier and Dr. Amalia Bastos from the University of St Andrews sought to test this ability to pretend in a structured experiment.
They devised a setup akin to a child’s tea party to evaluate Kanzi, a 43-year-old bonobo (Pan Paniscus) who has been reported to engage in pretend play and respond to verbal cues.
During the experiment, Kanzi and the researcher sat across from each other at a table adorned with an empty pitcher, cups, bowls, and jars, reminiscent of a tea party.
In the first task, two transparent cups, both empty, were accompanied by an empty pitcher.
The experimenter tilted the pitcher as if to “pour” juice into each cup, then pretended to dump juice from one cup, slightly shaking it to emphasize the action. They then inquired, “Where’s the juice?”
Kanzi consistently pointed to the cup that pretended to hold juice, even when its position was swapped, demonstrating his understanding of the task.
The researchers conducted a second experiment to rule out the possibility that Kanzi believed there was real juice in the cups, providing one cup with actual juice and another with pretend juice.
When asked what he preferred, Kanzi almost invariably pointed to the cup with real juice.
In a third experiment, the same concept was repeated without grapes.
Here, the experimenter pretended to take a grape from an empty container and placed it into one of two jars, then asked Kanzi, “Where are the grapes?” He accurately indicated the jar with the imaginary grapes.
While Kanzi wasn’t flawless, he consistently pointed to the correct locations.
“It’s fascinating and significant that the findings suggest great apes have the mental capacity to visualize things that are not present,” noted Dr. Bastos.
“Kanzi can conjure the notion of a pretend object while recognizing its lack of reality.”
“Imagination enriches the mental lives of humans,” added Dr. Krupenier.
“If we share some aspects of imagination with great apes, it compels us to reevaluate the presumption that other animals lead merely robotic lives, limited to the present moment.”
“These revelations will encourage us to cherish these intelligent, thoughtful creatures and ensure their preservation.”
For further details, refer to the study published in today’s issue of Science.
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Amalia Prime Minister Bastos et al. 2026. Evidence for object pretend expressions by Kanzi, a language-trained bonobo. Science 391 (6785): 583-586; doi: 10.1126/science.adz0743
Source: www.sci.news
