A first-of-its-kind study suggests bonobos, like humans, can understand someone else’s lack of knowledge - and adjust their actions accordingly.
If someone is supposed to give you a snack, but you know that they don’t know where that snack is, you would - obviously - communicate its location to them. This demonstrates the ability to understand another person’s specific lack of information and act accordingly - it's a concept called the “theory of mind”.
It’s involved in many sophisticated human behaviours and scholars have long debated whether close human relatives might also have this capacity.
Happily, this debate can now be put to rest. Certainly as regards bonobos.
Cognitive scientists Christopher Krupenye and Luke Townrow of Johns Hopkins University worked with three male bonobos named Nyota, Kanzi and Teco at the research institute Ape Initiative in Iowa.
For their study, 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 told NPR.
“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,” explained Krupenye.
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.
“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 told Scientific American. “This shows that they can actually take action when they realize that somebody has a different perspective from their own,” he explained to New Scientist.
The research was published in the journal Proceedings of the National Academy of Sciences.