An Ape Named Kanzi Shows That Imagination May Not Be Uniquely Human

Two empty cups sit on a table. A researcher mimes pouring invisible juice from an empty pitcher into both cups, then pretends to dump one back out. “Where’s the juice?” she asks.

Most animals would stare blankly or guess randomly. Kanzi, a 43-year-old bonobo, points decisively at the cup that still holds the pretend juice. He’s right. And he keeps being right (68% of the time across 50 tries) even though there’s never been any actual juice in either cup.

Kanzi isn’t confused. He isn’t fooled. He’s playing along.

For the first time, scientists have controlled experimental evidence that a nonhuman animal can engage in shared pretend play, the same kind of make-believe that unfolds at children’s tea parties. The discovery, published in Science, sharply narrows the line between human and animal cognition in one specific way: the capacity to represent pretend objects likely dates back 6 to 9 million years, to our common ancestor with apes.

“Our findings suggest that this capacity was likely within the cognitive potential of our last common ancestor with other apes,” wrote researchers Amalia P. M. Bastos and Christopher Krupenye from Johns Hopkins University. If they’re right, one basic building block of imagination isn’t a human innovation. We inherited it.

The Ape Who Learned to Talk (Sort Of)

Kanzi isn’t a typical bonobo. Since he was young, he’s lived at a research facility where he learned to communicate using lexigrams, a board with more than 300 symbols representing words. When someone says “Where’s the juice?” Kanzi understands. He can answer by pointing.

That linguistic ability made this experiment possible. Two-year-old human children can play the imaginary juice game because they understand the question and can respond. Without language, testing whether animals can pretend becomes nearly impossible. You’re left with anecdotes: like the wild chimpanzees who carry sticks and cradle them like babies, or the captive chimp who seemed to drag invisible toy blocks across the floor.

Those stories intrigued scientists, but they were easy to dismiss. Maybe the animals were confused. Maybe they’d just learned a behavior that looked like pretending. Maybe they didn’t realize the sticks weren’t actually infants.

Kanzi’s performance addresses those objections directly. The researchers ran two additional experiments to be sure. In one, they gave Kanzi a choice between a cup containing real juice and a cup they’d pretend-poured juice into. If Kanzi thought the pretend juice was real, he’d have no preference. Instead, he picked the real juice 14 out of 18 times. He knows the difference.

In another experiment, researchers repeated the test with grapes instead of juice. Same result. Kanzi tracked invisible grapes moving between transparent jars as if they were real, even though he could plainly see the jars were empty.

Moreover, Kanzi never got rewarded for correct answers during pretend trials, only during warm-up rounds with real food. The results rule out simple reinforcement learning or cue-following. Something more interesting was happening.

What It Means to Share a Mind Game with an Ape

The ability to pretend requires a particular mental trick: holding two contradictory ideas in your head simultaneously. The cup is empty. The cup contains juice. Both are true in different ways, and you don’t mix them up.

Psychologists call this cognitive decoupling: your brain keeps the real world separate from the imaginary one. That same mental machinery may power other sophisticated abilities: planning for the future (imagining tomorrow while living in today), understanding what others think (recognizing that someone else’s mental picture differs from yours), and reasoning through hypothetical scenarios (what if I did X instead of Y?).

For years, researchers have debated whether apes possess any of these abilities. Some studies suggest apes understand that others can hold false beliefs, but skeptics argue the animals might just be reading behavioral cues without truly reasoning about mental states. If apes can’t imagine, maybe they can’t truly think about thinking.

Kanzi’s performance makes it more likely that the cognitive tools are there. Whether those tools get used for planning, for understanding others’ perspectives, or for other kinds of abstract reasoning remains an open question. But finding that a bonobo can represent pretend objects suggests the foundation exists.

The Catch: Does Every Ape Have This Ability?

Kanzi’s language training makes him special, which raises an obvious question: can other apes do this, or did learning symbols somehow unlock a capacity that wouldn’t otherwise exist?

The researchers suspect most apes probably can pretend, but communication barriers make it hard to tell. Human toddlers develop pretend play around the same time they start talking, not because language creates imagination but because shared pretense requires coordination. You need some way to signal “we’re pretending now.”

Wild chimps carrying stick babies and treating them maternally suggests the capacity exists without human intervention. But scientists need cleverer experiments (perhaps borrowing methods from infant research, where babies reveal what they understand by looking longer at surprising events) to test apes who can’t respond to verbal questions.

If the ability to represent pretend objects turns out to be widespread among great apes, it would mean this capacity evolved in a common ancestor millions of years before humans existed. We didn’t invent it. We just happened to keep it.

Rethinking What We Share with Our Closest Relatives

Next time someone visits a zoo and watches an ape gazing into the distance, it’s worth considering what might be happening behind those eyes. Not just processing the immediate environment (the concrete wall, the watching crowd, the scheduled feeding time) but perhaps imagining something else entirely. Somewhere different. Some other situation.

That’s speculation, of course. But it’s no longer wild speculation. The experiments show that at least in structured play contexts with verbal scaffolding, Kanzi possesses the cognitive machinery to separate what is from what might be, to entertain possibilities that contradict reality without getting confused. Whether he uses that machinery beyond the experimental context, we can’t know. But he could.

And if he could, others might too.

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