Bonobos enjoy pretend tea parties and chimps think rationally: why apes are more like us than we ever thought

A series of stunning findings about great apes’ mental capabilities in recent years has transformed how we see our closest relatives

Clear plastic cups and pitchers adorned the wooden table in Des Moines, Iowa. Invisible juice was poured and presented to Kanzi, who enthusiastically chose the fake filled cup, playing along with the man who had come to visit. In many ways, it was the quintessential scene of a children’s imaginary tea party. Only Kanzi, at 44 years old, was a bonobo.

The experiment, carried out at the Ape Initiative facility in 2024, was the first to empirically test and document pretend play in a great ape species, with the results published in the journal Science in February. The study adds to an expansive repertoire of research over the past decade that has uncovered robust similarities between ape and human behaviours, upending long-held beliefs about how we distinguish ourselves from our closest kin.