At ZME Science, founder Mihai Andrei tells us that recent research shows that bonobos have a theory of mind. That is, they have ideas about what other life forms are thinking.

He goes further: That means humans are not nearly as exceptional as we think:

For centuries, we’ve thought we were unique amongst the animals on Earth. But the more researchers study other species, the more we realize that we’re probably not as special as we once thought. For instance, one ability once thought distinctly human was recognizing when someone else lacks information.

“Bonobos Know When You’re Clueless — Their Theory of Mind Explains Why,” February 3. 2025

Stop here for a minute

Is it true that “recognizing when someone else lacks information” has been thought to be a distinctly human trait?

Dogs sometimes sense that a human lacks information. Dogs have been known to take a human by the sleeve cuff and lead him somewhere — perhaps to where a puppy has fallen into a hole. The dog likely assumes that the human does not know that this has happened. And she is probably right. If animal psychologists have assumed that dogs couldn’t know that a human does not know something, they cannot have been very observant.

It’s an open question whether the dog needs a theory of mind in order to do that. She knows that the human will help, once he sees the problem. But how do we distinguish that awareness from general awareness of the life around her? For example, she doesn’t even consider asking the cat for help…

Thought: If the dog has no “theory of mind,” why does she know enough to ask the human for help and not the cat? Alternatively, if we are going to use the term “theory of mind,” we should mean more by it than what the researchers demonstrate below.

Bonobos and the three-cup problem

At Johns Hopkins University, Luke Townrow and Christopher Krupenye did a study of three male bonobos — Nyota, Kanzi and Teco — at Iowa’s Ape Initiative, published in the Proceedings of the National Academy of Sciences. At Smithsonian Magazine, Margherita Bassi explains:

For their study, published Monday in the journal Proceedings of the National Academy of Sciences, a bonobo would watch someone place a treat beneath one of three cups in proximity to Townrow. Sometimes, Townrow did not see which cup hid the treat, but the bonobo could only have the treat if Townrow gave it to him.

“We established a co-operative context to this task, because if I knew whether the treat or the food item was hidden, I would reveal it and then the bonobo would be able to receive that as a reward,” Townrow tells NPR’s Nell Greenfieldboyce.

“We predicted that if apes are really tracking ignorance, when their partners lacked knowledge they would be pointing more often and more quickly, and that’s exactly what they did,” Krupenye explains in a statement.

After the treat was hidden from view, Townrow would ask the bonobo where the food was, then wait ten seconds. If the bonobo had witnessed Townrow observing the placement of the grape, he would generally wait for the researcher to hand it over. If, however, the bonobo had witnessed the grape placement taking place without Townrow’s knowledge, he would quickly point to the correct cup.

“When Bonobos Know What You Don’t, They’ll Tell You,” February 5, 2025. The paper is open access.

So the bonobos know how to show a human where the treats they want are hidden. But look what is being made of it:

“The bonobos knew when their partner was ignorant, and they communicated proactively to make sure that their ignorant partner still made the correct choice,” Krupenye tells Scientific American’s Jack Tamisiea. “This shows that they can actually take action when they realize that somebody has a different perspective from their own,” he adds to New Scientist’s Sophie Berdugo. “They’ll Tell You”

And

This capacity is often cited as one of the defining features of human intelligence. The new findings suggest it may have evolved millions of years ago in a common ancestor we share with great apes. “Explains Why”

But if someone teaches a smart dog the same trick, wouldn’t evolutionary biologists have to reach much further back? And again, does it then show that dogs have a theory of mind too?

The theory of mind claims are similar to recent claims that ape tool use shows that the practice of smashing things with rocks developed in a common ancestor of apes and humans. But a number of animal life forms, including at least one bird, do that. So don’t we need to reach further back for the evolution of “tool use”?

So what’s the big deal about a theory of mind?

Neurologist Steven Novella offers some thoughts at his blog, Neurologica:

No one experiment like this is ever definitive, and it’s the job of researchers to think of other and more simple ways to explain the results. But the behavior of the bonobos in this experimental setup matched what was predicted if they indeed have at least a rudimentary theory of mind. They seem to know when the human researcher knew where the treat was, independent of the bonobo’s own knowledge of where the treat was.

This kind of behavior makes sense for an intensely social animal, like bonobos. Having a theory of mind about other members of your community is a huge advantage on cooperative behavior. Hunting in particular is an obvious scenario where coordination ads to success (bonobos do, in fact, hunt).

This will not be the final word on this contentious question, but does move the needle one click in the direction of concluding that apes likely have a theory of mind. We will see if these results replicate, and what other research designs have to say about this question. “

“Do Apes Have a Theory of Mind,” February 4, 2024

But it seems clear that the researchers have set out to show that bonobos have a theory of mind. They will inflate the importance of any finding that can be used for that purpose. That’s routine but the problem is that they (and others) may ignore findings that other life forms demonstrate a similar theory of mind. Perhaps that is because such findings are not seen so clearly as a blow against the stark reality of the human exception.

Note: The famous “mirror test” offered a similar scenario: An animal’s ability to recognize itself in a mirror was long supposed to be a test of awareness of self. Well, it turns out that some fish and ants pass the test but dogs and cats routinely don’t. Some children don’t pass it either.