Recent research, published in published in Proceedings of the Royal Society B, has uncovered significant insights into the cognitive abilities of bonobos. A study conducted by Johns Hopkins University’s Social and Cognitive Origins Group highlights that bonobos, much like humans, are capable of mentally tracking multiple individuals within their social circle, even when these individuals are out of sight. This ability plays an essential role in their social dynamics and communication.
Bonobos Demonstrate Social Intelligence in Controlled Experiments
In a groundbreaking series of hide-and-seek experiments, Kanzi, a bonobo, was tested on his ability to track the locations of two familiar caregivers. These caregivers, whom Kanzi knew well, would hide behind different barriers. Kanzi was then asked to point to the location of one of the caregivers based on a photo or the sound of their voice. The experiment was designed to test Kanzi’s ability to maintain mental representations of his caregivers, even when they were no longer in view.
“Kanzi very quickly understood the task and performed well,” said lead author Luz Carvajal, a Ph.D.
Student in the lab of Chris Krupenye, who studies apes’ knowledge of their social relationships. “Here he also performed above chance and especially well with one of his two caregivers.”
The results were striking. Kanzi was able to correctly identify the location of both caregivers based on either the visual or auditory cues, performing the task with remarkable accuracy.
“He does have the capacity to use voice as a marker for identity,” Carvajal added.
“This face matches this voice.”
This finding is significant because it shows that bonobos can integrate both vocal and visual information about their social group members in a unified way.
Understanding Social Cognition in Apes
The study of social cognition in apes has long been an area of interest for researchers. While it is widely known that humans have complex social networks, the extent to which non-human animals can maintain similar mental representations of group members is less understood.
Bonobos and other apes living in dense forests with large social groups need the ability to keep track of their groupmates—despite their frequent absence from view—because such information is crucial for navigating their environment.
“People think social intelligence is a thing that makes humans unique—that, because we have to manage so many different relationships, we might have a range of cognitive tools for doing so that will only be found in ultra-social species like humans,” says senior author Chris Krupenye, an assistant professor at Johns Hopkins who studies how animals think.
“But most of us who study apes have a strong intuition that, because the social world is so important for them too, they must, like humans, be keeping track of these critical social partners. They must share with us at least the foundations of our rich social intelligence.”
Previous studies have shown that apes, including bonobos, can recognize familiar individuals over long periods of time, even after being separated. However, this research goes a step further by testing whether apes can track multiple individuals simultaneously, which has never been tested before in a controlled environment. The results offer a significant step forward in understanding how these animals manage their social relationships, which are vital for their survival and reproduction.
Cognitive Evolution: What This Means for Human and Ape Similarities
This study provides crucial insights into the evolution of cognition. It suggests that the social intelligence required to track the locations and interactions of multiple individuals may be a trait shared by humans and their closest relatives, like bonobos. While humans have a highly developed sense of social cognition, it seems that other apes, like bonobos, also possess foundational cognitive tools for managing complex social networks.
“Across these studies the results suggest that Kanzi has a memory of these individuals that brings together their vocal and visual identities—who they are and what they sound like, and where they are in space,” Krupenye said.
“If he hears them he might imagine what they look like. If he sees them, he might bring to mind an idea of what they sound like. We think this is one integrated memory. He’s using the same photo prompt to refer to an individual whether he can see them or not.”
The ability to track multiple relationships could have been an evolutionary advantage for both humans and bonobos. In the wild, apes must be able to understand and react to the movements and behaviors of their group members to maintain social bonds and coordinate activities. This cognitive skill likely plays a crucial role in both survival and social cohesion within the group.
Krupenye also emphasizes the complexity of these animals:
“These animals are rich and complex. Even if we just want to understand ourselves better, there’s an urgency to this work and to saving this endangered species.”