5x5 Monkey Monday: Five ways trickster apes are more like us than we think

Do you know what I’m thinking? Understanding that other people are thinking different things to ourselves is called the theory of mind — it’s something children develop in their pre-school years and a challenge which often appears in autism, but it was once considered to be exclusive to humans.

New research has added to the evidence that some apes and other mammals have a theory of mind, understanding intention, deception and misunderstanding. The rise of career bullshitters like Donald Trump, Boris Johnson and Nigel Farage suggests that it may exceed the capacity of many adult humans. The research was published in the journal Science last week.

Gorillas are famous for their love of TV

1 It’s based on established tests for humans As any parent knows, young children can’t tell you what they’re thinking or feeling, and developmental psychologists have got around this for years by observing what children are looking at, based on evidence that if they’re looking at something, they’re thinking about it. It turns out the same approach works for many other animals with whom we can’t communicate directly, using laser eye-tracking to closely follow their gaze.

Japanese researchers found apes pay close attention to on-screen activity

2 Apes love a TV drama as much as human The researchers filmed scenarios designed to stimulate apes (not like that) showing conflict between pairs of human actors, one of whom is dressed on a King Kong outfit. It’s a nod back to the Japanese team’s pioneering research in 2015 which showed that apes remember and anticipate events in films. As yet, the researchers don’t know who the apes are rooting for.

Now they’ve used it to investigate simian understanding of deception

3 Chimps, bonobos and orangutans passed the test The study tracked the gaze of 40 chimpanzees, bonobos and orangutans, although only 30 of them paid enough attention to study. The videos are hardly The Wire, so maybe it just wasn’t sophisticated enough for them?

In the first video, Kong hits a person and then hides in one of two haystacks while the person watches. After the human leaves the scene, Kong exits the haystack and runs off screen. The person then reappears, apparently looking for the ape. A twist on this story had Kong briefly hiding in the other haystack before he left the scene.

The other story had Kong hiding a stone in one of two boxes as a person watches, but he steals it when they leave. Where will the person look when they return? The twist scenario shows Kong moving the stone to the other box in secret.

4 The apes predicted what people were thinking Two-thirds of the apes watching the first video looked at the haystack where the human falsely thought the human was hiding, with similar results for the hidden stone story.

The alternative scenarios worked as controls to test that the apes weren’t just looking at the last place they saw the key object in the story.

It’s not entirely clear how far the theory of mind extends in apes. Some research has suggested they might have an implicit understanding of deception rather than a conscious concept of the intention to deceive, but other researchers point to widespread use of deception in apes’ social behaviour.

5 No-one knows what creates the theory of mind Cognitive science has yet to pinpoint how the theory of mind arises in humans, let alone apes. Some researchers have proposed that theory of mind requires language to understand how people may talk about and misrepresent their beliefs and emotions, rather than just observing the behaviour of others.

That’s difficult enough with children, who may understand more than they express about what’s said around them, let alone with apes whose linguistic abilities are as heavily debated as their cognitive powers.