Bonobo Kanzi Plays Pretend Tea Party in New Study

Researchers at Johns Hopkins University sat across from a 43-year-old bonobo named Kanzi at a simple table. They poured from empty pitchers into clear cups and asked him to find the pretend juice. Kanzi pointed to the right spots most times, showing he could track things that were not really there. The tests took place at the Ape Initiative facility in Georgia, where Kanzi lived. This work came out in early February 2026 and points to apes having a mental skill once seen as human-only.

Background

Kanzi grew up around people and learned to talk with them using lexigrams, which are symbols on a board that stand for words. He combined those symbols in new ways and even made basic stone tools. People who studied him for years said he played pretend before, like acting out chases or other games. But no one had tested it in a clear way until now.

The team behind the study included Amalia Bastos from the University of St Andrews in Scotland and Christopher Krupenye from Johns Hopkins in Baltimore. They met Kanzi in 2023. Right away, he used his lexigram board to ask them to chase each other. Even though they only pretended, Kanzi watched with interest. That got them thinking about his ability to handle make-believe.

For a long time, experts said imagination set humans apart. Kids as young as two turn boxes into spaceships or empty cups into tea. They know it is not real but play along anyway. Chimps and bonobos seemed smart in other ways, like using tools or remembering where food is hidden. But pretend play stayed in the human camp. This study changes that view by showing clear evidence with Kanzi.

Bonobos sit close to us on the family tree. They split from our line about 6 to 9 million years ago. Kanzi was special because he spent his life with humans, learning their ways from a young age. He passed away last year at age 44, but his tests give a window into ape minds.

Key Details

The main tests looked like a child's tea party. Kanzi and a researcher faced each other across a table. They used empty clear cups, pitchers, bowls, and jars so everyone could see nothing was inside.

The Juice Test

In the first setup, the researcher took a clear empty pitcher and tipped it over two empty clear cups. Pretend juice went into each one. Then, the researcher acted like they poured the juice from one cup back into the pitcher. They moved the cups around a bit and asked Kanzi, 'Where is the juice?'

Kanzi pointed to the cup that still had the pretend juice. He got it right 68 percent of the time. That beat random chance by a wide margin. To check if he just saw something real, they added a twist. One cup got real orange juice, Kanzi's favorite. The other got pretend juice from the empty pitcher. When asked what he wanted, Kanzi picked the real juice nearly 80 percent of the time. He knew the difference.

The Grapes Test

They ran a similar game with grapes. Empty bowls sat on the table. The researcher pretended to scoop pretend grapes into two bowls from a clear empty jar. Then they acted like they took the grapes out of one bowl. Kanzi pointed to the bowl with the make-believe grapes most of the time.

These steps ruled out other ideas. Kanzi was not just copying moves or thinking old eyes tricked him. He held two thoughts at once: this is pretend, but it acts real. The team ran many trials to make sure.

"It really is significant that their mental lives go beyond the here and now," said Christopher Krupenye, a co-author of the study. "Imagination has long been seen as a critical element of what it is to be human but the idea that it may not be exclusive to our species is really transformative."

Not all experts agree it proves full pretend play. Michael Tomasello from Duke University, who did not work on the study, said picking between pretend choices might not mean Kanzi made up the game himself. Stronger proof would show him starting the pretense on his own.

What This Means

This work opens questions about animal minds. If Kanzi could imagine, maybe other apes can too. It suggests the skill goes back millions of years to when our lines split. Researchers now plan tests on thinking about the future or guessing what others think.

Kanzi's human-like upbringing makes some wonder if he learned it from us. Future studies might test young apes raised by their own kind. That could show if imagination comes natural or needs people to spark it.

The findings touch bigger ideas. Jane Goodall once showed chimps use tools, and that shifted views on human smarts. This could do the same for imagination. It asks us to rethink lines between us and apes.

For apes in the wild, facing threats like habitat loss, knowing their mental world matters. It could shape how we protect them or study conservation. Bastos said Kanzi paved the way for more work.

"Kanzi opened this path for a lot of future studies," said Amalia Bastos, another co-author.

The study pushes science to look deeper into primate thoughts. Teams want to see if apes plan ahead or picture past events. Each step builds on what Kanzi showed at that table with empty cups.