Bonobos Demonstrate Capacity for Pretend Play, Study Finds

Research suggests great apes possess imagination skills once thought unique to humans.

Published on Feb. 9, 2026

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A new study published in the journal Science provides experimental evidence that bonobos, a species of great ape, are capable of pretend play similar to human children. Researchers at Johns Hopkins University conducted a series of tests with a bonobo named Kanzi, who demonstrated the ability to distinguish between real and imaginary objects, including correctly identifying which cup contained pretend juice and which jar held a fictitious grape.

Why it matters

This study challenges the long-held belief that the capacity for imagination and pretend play is unique to humans. The findings suggest great apes possess more advanced cognitive abilities than previously understood, lending support to anecdotal reports of apes engaging in simulated behaviors in both captive and wild settings.

The details

In the experiments, Kanzi was presented with various setups involving real and imaginary objects, and was able to correctly identify the containers holding the pretend items. Researchers say Kanzi's language-training and participation in prior cognitive studies made him a particularly suitable subject for this research. While the results cannot be immediately generalized to all bonobos or other great ape species, the study provides robust experimental evidence that at least some apes are capable of representing and reasoning about imaginary scenarios.

  • The experiments were conducted in 2024, when Kanzi was 43 years old, a year before his death.
  • Previous anecdotal observations of ape pretend play were reported as early as the 2000s.

The players

Kanzi

A bonobo who participated in the pretend play experiments at Johns Hopkins University. Kanzi was language-trained and had previously demonstrated advanced cognitive abilities in other research studies.

Amalia Bastos

One of the researchers who conducted the pretend play experiments with Kanzi at Johns Hopkins University. Bastos is now a lecturer at the University of St. Andrews in Scotland.

Christopher Krupenye

The other researcher who collaborated with Bastos on the pretend play study with Kanzi at Johns Hopkins University.

Nicholas E. Newton-Fisher

A primate behavioral ecologist at the University of Kent in England who was not involved in the study but provided commentary on the findings.

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What they’re saying

“Throughout his life, Kanzi repeatedly demonstrated skills that required us to reevaluate our understanding of ape cognition. It seems suitable, therefore, that he has also provided experimental evidence of imagination. This is an exciting finding that lends experimental support to anecdotal reports from both captive and wild-living individuals.”

— Nicholas E. Newton-Fisher, Primate Behavioural Ecologist, University of Kent (CNN)

“Kanzi was a particularly good subject because he was language-trained. He was one of very, very few apes who understood verbal prompts, which he responded to using a lexigram of over 300 symbols.”

— Amalia Bastos, Researcher, University of St. Andrews (CNN)

What’s next

Researchers say further investigation is needed to determine if the capacity for pretend play extends beyond Kanzi to other bonobos and great ape species.

The takeaway

This study provides experimental evidence that the ability to engage in imagination and pretend play is not unique to humans, challenging long-held assumptions about the cognitive capabilities of great apes. The findings suggest we may be systematically underestimating the mental abilities of our closest living relatives.