Scientists have found that chimpanzees’ performance on computer tasks is influenced by the number of people who observe them and publish their findings on the Internet. iScience magazine.
When people have an audience watching them, their performance can change for the better or worse. The new study suggests that this ““public effect” It predates the development of reputation-based human societies, researchers say.
“It was very surprising to find that chimpanzees are influenced by members of the public in performing tasks by human audience members” says Christen Lin of Kyoto University in Japan. “One might not expect a chimpanzee to be particularly concerned if another species observes them performing a task, but the fact that they appear to be influenced by human audiences even at depending on the difficulty of the task task suggests that this relationship is more complex than we might have initially expected.”
The researchers, including Shinya Yamamoto and Akiho Muramatsu, wanted to find out whether the public effect, often attributed in humans to reputation management, could also exist in a non-human primate. They knew that people pay attention to those who watch them, sometimes even unconsciously, in ways that affect their performance. Although chimpanzees live in hierarchical societies, It was unclear to what extent they too might be influenced by those who observed them.
“Our study site is special because chimpanzees often interact with humans and even enjoy their company, participating almost daily in various touch-screen experiments to obtain food rewards,” says Muramatsu. “Therefore, we saw an opportunity to not only explore possible similarities in audience-related effects, but also in the context of chimpanzees sharing unique bonds with humans“.
The researchers made the discovery after analyzing thousands of sessions in which chimpanzees completed a task on the touch screen over six years. They found that in three different number-based tasks, the chimpanzees performed better on the more difficult tasks as the number of experimenters observing them increased. Conversely, they also found that, on easier tasks, chimpanzees performed worse when they were observed by multiple experimenters or other familiar people.
The researchers point out that it is not yet clear what specific mechanisms underlie these audience-related effects, even in the case of humans. They suggest further studies in non-human apes can offer more insight into how this trait evolved and why it developed.
“Our findings suggest that the degree of concern humans have for witnesses and members of the public may not be so specific to our species,” Yamamoto says. “These characteristics are a key part of how our societies rely heavily on reputation, and if chimpanzees also pay close attention to audience members while carrying out their tasks, it stands to reason that these audience-based characteristics could have evolved before reputation-based societies emerged in our great ape lineage“.
Interview: Exploring the Public Effect in Chimpanzees with Dr. Christen Lin
Editor: Welcome, Dr. Lin. Thank you for joining us today to discuss your fascinating research on chimpanzees and the influence of human observers. Your study published in iScience has garnered a lot of attention. Can you start by explaining what the “public effect” is?
Dr. Lin: Thank you for having me! The “public effect” refers to the phenomenon where an individual’s performance on a task is influenced by the presence of an audience. This effect is well-documented in humans, where people often perform differently—sometimes better, sometimes worse—depending on who is watching them. Our research aimed to explore whether this effect also exists in chimpanzees.
Editor: That’s intriguing! So, how did you conduct your research to determine if chimpanzees are affected by human observers?
Dr. Lin: We designed a series of touch-screen experiments where chimpanzees had to complete tasks to earn food rewards. The unique aspect of our study site is that chimpanzees often interact with humans, and they seem to enjoy these interactions. We varied the presence of human audience members to see how their performance would change depending on the difficulty of the tasks and the number of observers present.
Editor: That sounds like an excellent setup. What were your main findings?
Dr. Lin: One of the most surprising results was that chimpanzees indeed exhibited changes in performance based on the number of humans watching. It seems that they are more affected by an audience than we initially thought. For example, in more difficult tasks, their performance could deteriorate under observation, while in easier tasks, they often performed better. This suggests that their cognitive processes may involve a complex understanding of social dynamics, even if those dynamics differ from those in human societies.
Editor: That is quite noteworthy! Given that chimpanzees live in hierarchical societies, did this influence their reactions when observed?
Dr. Lin: Absolutely. While chimpanzees are accustomed to the hierarchy within their groups, the introduction of human observers adds a layer of complexity. It’s interesting because it opens up questions about whether they preferentially respond to certain individuals or if the sheer number of observers matters more. Our findings indicate that they might be sensitive to the social presence of others, independent of direct social hierarchies.
Editor: It seems your research bridges two worlds—the behaviors of chimpanzees and human social dynamics. Do you think this could give us insight into the evolutionary roots of reputation management?
Dr. Lin: That’s a critical angle to consider. Our results suggest that the awareness of an audience may predate human sociocultural evolution. Understanding these behaviors in chimps can provide clues about the origins of social cognition, reputation management, and how these traits may have developed within our species.
Editor: Fascinating! What do you envision as the next steps for this line of research?
Dr. Lin: We aim to delve deeper into the cognitive mechanisms that underpin these behaviors. Further studies could explore how chimpanzees process their goals and tasks when they know they’re being watched, not only from humans but also from their peers. It would also be crucial to experiment in different contexts—like competitive situations versus cooperative tasks—to better understand the nuances of their social behavior.
Editor: Thank you, Dr. Lin, for sharing your insights today. Your work not only enriches our understanding of primate behavior but also prompts us to rethink our own social interactions. We look forward to your future findings!
Dr. Lin: Thank you! I appreciate the opportunity to discuss our research, and I’m excited to share more in the future!