Can apes use their imagination and play make-believe?

Researchers have observed a bonobo, Kanzi, engaging in imaginative play. The team set up a series of tea-party scenarios with Kanzi, presenting him with two empty cups and pretending to fill them with juice. They pretended to pour one cup back into an empty jug and asked Kanzi which cup contained juice. Kanzi correctly identified the cup with “juice” in 34 out of 50 trials, which is more than chance.

These results suggest that Kanzi understood the concept of the imaginary game and was able to “play” along. The researchers checked that Kanzi understood that the juice was imaginary by allowing him to choose between empty cups and actual juice. They were able to duplicate the game with imaginary grapes instead of juice. The test was nearly identical to methods for testing imagination in human children.

But it’s unclear if these results could be duplicated in wild bonobos who haven’t been language-trained. However, these results do suggest that the ability to “make believe” can be traced back to our last common ancestor with bonobos (around six to nine million years ago). Humans are not unique in our ability to create imaginary or hypothetical situations.

What about other apes? Researchers have documented young chimps carrying sticks as if they were infants (cradling and grooming them) and pushing pretend blocks across the floor. There are examples of imaginative play in captive gorillas (Koko) and orangutans (Chantek). Apes are also known to select tools and wait hours to use them: a behaviour that requires an understanding of future scenarios.