Humans, including Bonobos, are aware of their ignorance and strive to aid humans in their endeavors

Ars Technica

There’s some mixed evidence that other animals have a limited theory of mind, but there are alternate interpretations for most of it.
The work clearly showed that the bonobos could tell when their human partner was ignorant.
The bonobos were first familiarized with the setup and got to experience their human partner taking the treat out from under the cup and giving it to them.
I know what you’re thinking All of that indicates that the bonobos can make inferences about the state of knowledge of a human partner and will adjust their behavior accordingly.
The bonobos were cooperating with a human, something that never occurs in the wild (the animals are pretty unlikely to ever come across food hidden under plastic cups, for that matter).

NEGATIVE

What is known as a “theory of mind”—the capacity to deduce another person’s mental state and modify our behavior according to our expectations of what they know and are thinking—is necessary in many human societies. We still rely on it for everything from avoiding bumping into people on the street to navigating complex social situations, even though we don’t always get it right—it’s easy to get confused about what someone else might be thinking.

There are conflicting theories regarding the majority of the evidence, but there is some conflicting evidence that other animals have a limited theory of mind. Therefore, two Johns Hopkins researchers, Luke Townrow and Christopher Krupenye, devised a method to test the ability of bonobos, some of our closest living relatives, to deduce the mental state of a human they were collaborating with. It was evident from the work that the bonobos were able to detect ignorance in their human companion.

You see it now.

The experimental method is fairly straightforward and uses a setup that is common to street hustlers: three cups with a treat underneath one of them. There isn’t a sleight of hand in this instance, though, because the chimp can observe as one experimenter places the treat beneath a cup, and every cup stays in place during the test.

A second human experimenter must cooperate, though, in order to receive the treat. The bonobo must be given the treat underneath the cup after the correct cup has been identified. In certain experiments, this person can see the treat being concealed behind a clear partition and thus knows its precise location. However, in others, the partition is solid, making it impossible for a human to determine which cup might be concealing the food.

Because of this configuration, the bonobo will always be aware of the location of the food and will also be able to determine whether a human does the same.

After getting acquainted with the setup, the bonobos had the opportunity to watch their human partner retrieve the treat from beneath the cup and present it to them. After they became accustomed to the procedure, they observed the food being concealed without a companion present, indicating that they hardly ever took any food-directed actions without a valid reason. In contrast, they were roughly eight times more likely to indicate the cup with the food underneath it when their human partner was around.

Therefore, the main question was whether the bonobos behaved differently when the experiment was conducted behind the solid partition than when their human partner could see the location of the hidden food.

Yes, was the response. In the ten seconds between removing the partition and the researcher checking the cups for food, bonobos pointed more frequently and were quicker to begin pointing to the hidden food when the partition was solid. When the solid partition was used, one of the three bonobos that were tested became impatient and pointed a lot, even if their partner was unaware of which cup contained the food.

I understand what you’re thinking.

All of that suggests that bonobos are able to infer information about a human partner’s level of knowledge and will modify their behavior accordingly. So, the animals have a theory of mind that helps them do things, at least on some level.

Nevertheless, the experiment produced a rather fabricated scenario. Given how unlikely it is that the bonobos will ever find food concealed beneath plastic cups, the fact that they were collaborating with a human is something that never happens in the wild. In wild populations, there are hints that bonobos will modify the warnings they issue to their peers if those peers are not aware of the danger. This is not a criticism of the work, which was intended to test for comparable behavior in a controlled setting; rather, it serves as a reminder that we should exercise caution when extrapolating these findings until we have proof that doing so is justified.

Teco, the bonobo, and his habit of constantly pointing at the food served as a reminder of yet another warning: animals are unique and may have peculiarities. We don’t have a good idea of the whole range of behavior that could be observed in a sizable population of bonobos because we have only tested three of them.

However, the work shows that some of our close relatives possess some elements of a theory of mind, and in certain situations, they will use it to their advantage.

2025 PNAS. 10.1073/pnas is the DOI. 2412450122 (DoIs related).

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