Scientists say bonobos can play make-believe

Have you ever pretended that the floor is lava, or that a hairbrush is a microphone? Maybe you've poured tea for a teddy bear that wasn't really there, or turned a cardboard box into a spaceship.

Pretending like this is something most children do lots of – it's fun, creative, and helps make sense of the world around us.

For a long time, scientists thought this kind of make-believe was something only humans could do.

Animals, they believed, could copy actions or learn tricks, but they couldn't imagine things that weren't really there.

Now, new research suggests they may have been wrong. Scientists studying bonobos – one of our closest animal relatives – have found evidence that these apes might be able to pretend too.

Bonobos are great apes and are closely related to chimpanzees and humans.

In the past people have reported seeing the apes act as if they were using imaginary objects, but scientists were not sure if the animals were really pretending or just repeating actions they had learned before.

To investigate, researchers worked with a bonobo called Kanzi, and set up simple tests to see if he could understand make-believe.

They published their findings in the journal Science.

First, Kanzi learned to point to cups that contained real juice. Once he understood this, the scientists tried something new.

They showed him two empty, clear cups and pretended to pour juice into them using an empty jug. Then they pretended to pour the juice out of one cup again. Kanzi was asked to choose the cup that should still have juice in it.

He chose the correct cup in 34 out of 50 attempts. He was not given a reward, which showed he was not just copying what the humans did. This suggested he understood the idea of pretend juice.

In another test, Kanzi was given one cup with real juice and one empty cup. Even when the scientists pretended to fill the empty cup, Kanzi usually (14 out of 18 times) chose the cup with real juice.

Scientist say this showed he could tell the difference between something real and something pretend.

Dr Amalia Bastos from the University of St Andrews and co-author of the study said the research "shows that animals are capable of understanding pretence in a controlled experimental setting, which hadn't been done before."

She added that because humans and bonobos share this ability, it may go back to a common ancestor that lived "somewhere between six and nine million years ago".

Now the team behind the research say more research is needed, especially with apes that have not been trained like Kanzi.