Bonobo’s Demonstrate Higher Intellectual Abilities Through Communication

        Video of bonobo cognition study conducted by Townrow and Krupenye

 

For many decades scholars believed that nonhuman primates did not have the same level of intelligence of humans.  Nonhuman primates were passed off as wild and simple creatures that were inferior to modern humans.  Long gone are those days and inaccurate ideas, though.  This blog has addressed various aspects of nonhuman primates’ cognitive (or intellectual) abilities, including various ape species’ ability to learn and communicate with sign language and ape species’ ability to combine calls to communicate more than one message.  Today’s blog post adds one more line of evidence that demonstrates nonhuman primates, particularly apes, are smarter than we originally realized.  Apes demonstrate a cognitive ability known as theory of the mind.

 

Theory of the mind is understanding that someone lacks information and moving forward appropriately (e.g., providing them the information or keeping the information secret, depending on the circumstances).  Ultimately, the purpose of theory of the mind is that it acts as a means of cooperation among individuals.  People will share information with each other, particularly those ignorant of a situation, in order to incorporate them into the group and strengthen group bonds. 

 

This ability had been hinted at as being present among various wild ape species from observations by primatologists, but it was unclear if what the primatologists were seeing was indeed cognition or mimicry.  For example, primatologists observed cooperative hunting among chimpanzees wherein one member would alert the group to either a dangerous predator or tasty prey, but it was unclear if others would mimic the actions of the one or if they understood what was being communicated (e.g., running because everyone was running or running because they understood the purpose).  This led two researchers out of John Hopkins University, Luke Townrow and Christopher Krupenye, to test whether or not nonhuman primates did indeed have cognitive abilities linked to the theory of the mind.

 

Townrow and Krupenye conducted their experiment at the Ape Initiative in Iowa.  They selected three male bonobos, Nyota, age 25; Kanzi, age 43; Teco, 13, to engage in their experiment.  They set up their experiment to involve three overturned cups placed on a table, and an experimenter would place a treat under one of the cups.  They then split the experiment into two trials.  In the first trials both a human and a bonobo would watch the experimenter place the treat under the cup.  The human would have to retrieve the treat to give to the bonobo.  This was done easily since the human watched where the treat was placed and could quickly retrieve it.  In the second trials deception was introduced.  This time only the bonobo saw where the treat was placed (as a barrier was placed in front of the human).  The bonobo would point to the cup and the human would wait 10 seconds, perusing the three cups to figure out which one had the treat.  As this trial was repeated the bonobo would point more quickly to the cup with the hidden treat, recognizing the human’s ignorance to where the treat was placed.  A video of the experiment is provided above.

 

The researchers concluded that the results provide definitive evidence of ape species’ ability to understand different perspectives from their own (i.e., another individual does not know something or understands the situation differently).  This further supports the previous observations among wild ape species, which means that cooperation among wild apes is not based on imitation but cooperation.  This study demonstrates that the cognitive ability of theory of the mind must have been present within the common human-ape ancestor, and it also shows that language is not required for the existence of this cognitive ability.  Ultimately, this revolutionizing our ideas and understandings of apes and humans, particularly related to intelligence.

 

Works Cited

Bassi, Margherita. "When Bonobos Know What You Don’t, They’ll Tell You. It’s a Sign of a Cognitive Ability Called ‘Theory of Mind’." Smithsonian Magazine 5 February 2025. Electronic.

Nield, David. "Bonobos Know Something You Don't Know, And Are Willing to Tell For a Price." Science Alert 7 February 2025. Electronic.

Townrow, Luke A. and Krupenye, Christopher. "Bonobos point more for ignorant than knowledgeable social partners." Proceedings of the National Academy of Sciences (2025): 6. Electronic.