Imagine a world where your teddy bear has a secret life, or your stuffed animals attend elaborate parties when you're not looking! For a long time, we thought this kind of imaginative, make-believe play was a uniquely human trait, something only our children could do. But here's where it gets fascinating: a groundbreaking study suggests that this ability might be shared by our closest relatives in the animal kingdom!
Think about how children love to engage in pretend play – hosting imaginary tea parties, teaching their stuffed animals, or running make-believe shops. Now, a new scientific exploration hints that this kind of simulated play isn't just for human youngsters. It appears that great apes, our intelligent primate cousins, also possess this remarkable skill.
The compelling evidence for this comes from a special bonobo named Kanzi. He was the star participant in a series of three experiments designed to look like pretend tea parties, conducted by dedicated researchers at Johns Hopkins University in Baltimore, Maryland.
Before this study, scientists had already observed individual apes engaging in solitary play, which sparked the idea that animals might be capable of simulated play. Study authors Amalia Bastos and Christopher Krupenye pointed out in their publication in the esteemed journal Science that these earlier observations, while intriguing, left room for interpretation.
For instance, in one earlier piece of research, a young chimpanzee in captivity was observed on two separate occasions between 2003 and 2004. This chimp was seen dragging what appeared to be imaginary blocks across the floor, much like it would when playing with actual wooden blocks. Another fascinating observation involved female chimpanzees in their natural habitat in Uganda. Over a 14-year period, these wild apes were seen carrying and interacting with sticks as if they were baby dolls, mirroring how mother chimpanzees care for their infants.
But here's the part that sparked debate... The researchers noted that these earlier observations were largely anecdotal. This meant there was a possibility that the apes were simply imitating behaviors they had witnessed from humans, rather than genuinely engaging in imaginative play. Another consideration was whether an ape might mistake a picture of a blueberry for a real one, or if the reward of playing with wooden blocks was so high that the ape would repeat the action even without the blocks present.
To move beyond these doubts and gather more concrete proof, the researchers devised a more controlled approach. In 2024, they conducted a series of tests using juice and grapes with Kanzi, who was 43 years old at the time, just a year before his passing.
In the first experiment, Kanzi was presented with two squirt bottles: one empty and one filled with juice. He was asked to identify the bottle containing the juice. Across 18 trials, Kanzi consistently picked the correct bottle every single time!
Next, an experimenter showed Kanzi two empty, transparent cups. They then pretended to pour juice from an empty pitcher into each cup. After this, they poured the 'imaginary' juice from one cup back into the pitcher. When asked, "Where's the juice?" Kanzi correctly selected the cup that still held the imaginary juice 68% of the time. This success rate is significantly higher than what you'd expect from random chance.
And this is the part that really clarifies things... To ensure Kanzi wasn't just assuming there was real juice in the empty cups, the researchers conducted a second task. In 18 trials, Kanzi was given one cup with actual juice and another empty cup with imaginary juice. When asked, "Which one do you want?" Kanzi chose the cup with real juice 14 out of 18 times. This clearly demonstrated that he could distinguish between real and pretend juice.
The final experiment used a similar setup but replaced juice with a grape. Kanzi was remarkably successful, identifying the jar with the fictitious grape 68.9% of the time, and he did so even more quickly than in the juice experiment.
The researchers concluded that their "findings suggest that the capacity for representing pretend objects is not uniquely human."
Nicholas E. Newton-Fisher, a primate behavioral ecologist at the University of Kent, commented that Kanzi "repeatedly demonstrated skills that required us to reevaluate our understanding of ape cognition." He added that it's fitting that Kanzi has now provided experimental evidence of imagination, which lends strong support to the anecdotal reports from both captive and wild apes.
Kanzi, who sadly passed away in March, was an exceptional subject for this study because he was language-trained. Amalia Bastos, now a lecturer at the University of St. Andrews, mentioned that Kanzi was one of very few apes who understood verbal commands and responded using a lexigram with over 300 symbols.
As part of the Ape Initiative research center, Kanzi had previously participated in other cognitive studies. One such study in 2025 revealed that bonobos could point out a hidden object if they noticed their human companion didn't know its location.
However, the researchers acknowledge that because Kanzi was the only bonobo tested, it's not yet certain if these results apply to all other apes. Bastos expressed that given the numerous anecdotal reports, she wouldn't be surprised if this ability extends beyond Kanzi.
Newton-Fisher echoed this sentiment, stating that while generalizing from Kanzi to other bonobos and ape species requires further study, he suspects "we systematically under-appreciate the cognitive abilities of these species."
He also wisely cautioned that while we often compare adult ape mental abilities to human children to gauge their cognitive sophistication, apes have their own unique minds and brains. Therefore, "how – imagination, for instance – manifests in an ape may not be a ‘cut-down’ version of the equivalent ability in humans."
What do you think? Does this study change your perception of ape intelligence? Are there other behaviors you've observed in animals that make you wonder about their inner lives? Share your thoughts in the comments below – we'd love to hear your perspective!
