The dynamics of human cooperation have long intrigued scientists. Conventional wisdom suggests that as group size increases, cooperation tends to diminish. However, a groundbreaking study from the RIKEN Center for Brain Science (CBS), published in Communications Psychology on December 23, challenges this belief. The research reveals that, contrary to what was once assumed, larger groups can actually promote greater cooperation, thanks to our brain’s fluid social connections and innate prosocial instincts.
Humans are inherently social creatures. Our ability to form and navigate complex social relationships is a critical aspect of our survival and success. This social behavior is deeply rooted in the workings of our brains, which are relatively large compared to other animals. As such, humans have the capacity to form much larger and more intricate social networks. In fact, the size of an animal’s brain often correlates with the size of its social group, with humans standing out for their unique ability to thrive in extensive, dynamic communities.
Challenging Traditional Assumptions: Cooperation in Larger Groups
For decades, it was widely accepted in social science that cooperation declines as group size increases. The argument was based on the idea that in larger groups, individuals find it harder to maintain personal relationships, recall past interactions, and build the trust necessary for cooperative behavior. When groups grow too large, the risk of one individual’s betrayal or selfish behavior might go unnoticed, and the sense of responsibility to the collective diminishes.
Earlier studies seemed to support this notion. They suggested that as groups expand, members are less likely to cooperate because they are unable to maintain the strong, trusting relationships that are often crucial to collaborative efforts. However, the research conducted by Rei Akaishi and his team at RIKEN CBS presents a strikingly different view, overturning the conventional understanding of group dynamics and cooperation.
The RIKEN Study: Exploring Cooperation in Larger Groups
To test their hypothesis, Akaishi and his colleagues designed a study in which 83 participants engaged in the classic prisoner’s dilemma game. In this game, individuals must decide whether to cooperate with others for mutual benefit or act selfishly. The participants were divided into groups of varying sizes, from two to six people, and given the option to leave groups they found undesirable or remove uncooperative members.
During the game, the researchers monitored participants’ brain activity using functional magnetic resonance imaging (fMRI). What they discovered was surprising: participants in larger groups cooperated more frequently, with 57% of all decisions being cooperative. Interestingly, cooperation rates increased as the group size grew, suggesting that larger groups can indeed foster greater collaborative behavior.
Memory, Decision-Making, and Prosocial Instincts
While the size of the group did not directly dictate cooperation, the study revealed that it significantly influenced how individuals managed memory and made decisions during social interactions. The researchers found that when participants had difficulty recalling past interactions, they still tended to prioritize cooperation over caution. This behavior suggests that, even in the absence of clear memory, humans default to prosocial instincts, valuing cooperation to maintain group harmony.
The brain scans further elucidated the mechanisms behind these decisions. Regions such as the fusiform gyrus and precuneus were involved in processing memories of prior interactions, while the nucleus accumbens linked those memories to feelings of reward. More importantly, the prefrontal cortex played a pivotal role in evaluating these memories against personal inclinations, guiding decisions about whether to cooperate with someone who may have betrayed the participant before.
When memory recall was less reliable, the brain seemed to favor cooperation as a default mode. This instinctual push toward collaboration may be a strategy to maintain group cohesion and prevent disruption in larger social settings. Essentially, even when participants were uncertain about past interactions, their brain encouraged them to engage in behaviors that would support cooperation and harmony within the group.
Flexible Social Connections and Cooperation
These findings offer a fresh perspective on how humans cooperate in larger groups. Instead of relying solely on stable, long-term relationships to foster trust, humans can thrive in groups through flexible and fluid social connections. This adaptability enables individuals to make decisions based on immediate interactions and memories, allowing for smoother collaboration even in evolving or temporary group structures.
This insight holds significant implications for today’s society, where digital platforms and online communities often operate with dynamic, shifting relationships. The study suggests that fostering flexibility in social connections—allowing individuals to form and adjust relationships freely—could be key to improving cooperation in both digital and physical environments.
Practical Applications: Enhancing Teamwork and Group Dynamics
The findings of this study have practical implications for enhancing teamwork and group cooperation in various settings. According to Akaishi, the results could help improve collaboration in schools, workplaces, and online environments. By designing systems that allow people to form and adjust connections naturally, rather than adhering to rigid, fixed group structures, organizations could see more effective collaboration and better group dynamics.
In the context of workplaces, this flexibility could lead to more fluid, adaptive teams that adjust to challenges and opportunities as they arise. In educational settings, this might foster more collaborative learning environments where students can work together more effectively, regardless of the size of their groups.
Akaishi also emphasizes that digital platforms, where users form and reform groups constantly, could benefit from understanding the psychological underpinnings of cooperation in larger groups. By allowing users to forge and modify connections dynamically, these platforms could cultivate healthier, more collaborative communities, both in online discussions and in project work.
Evolutionary Insights into Human Cooperation
The study also sheds light on how humans evolved to cooperate in increasingly large and complex societies. According to Akaishi, our ability to cooperate in larger groups can be traced back to adaptations in our cognitive and social capacities. Humans have developed sophisticated memory systems and prosocial instincts, which enable us to navigate uncertain social landscapes and form effective collaborations even in the absence of perfect knowledge about others.
As Akaishi explains, these findings help explain why humans are capable of thriving in diverse, multifaceted social networks. Whether in large organizations, schools, or communities, our brains have evolved to enable cooperation, even in the face of uncertainty or incomplete information.
Future Directions: Studying Cooperation in Real-World Settings
Akaishi and his team plan to explore these findings further by testing them in real-world settings, such as schools and businesses. They are particularly interested in how factors like culture, leadership, and individual personalities influence group behavior. These studies aim to uncover more about the practical strategies that can help foster cooperation and harmony in diverse communities, whether physical or virtual.
“The ultimate goal of our research is to provide actionable insights that can improve teamwork and group dynamics,” says Akaishi. “We hope our findings will lead to practical strategies for creating more harmonious and productive communities in a variety of settings.”
Conclusion: Rethinking Cooperation in Larger Groups
The study conducted by RIKEN’s Center for Brain Science challenges the long-held belief that larger groups undermine cooperation. By showing that flexibility in group connections and innate prosocial instincts can foster greater collaboration, the research opens new avenues for understanding human social behavior. Whether in schools, workplaces, or online communities, this study suggests that dynamic, adaptable social networks can promote stronger cooperation, even in large groups.
As we continue to evolve in an increasingly connected world, this research highlights the importance of recognizing the natural human tendency toward cooperation. By embracing this flexibility in our social structures, we can create more cooperative and productive environments, helping individuals and groups succeed together.
Reference: Wojciech Zajkowski et al, A neurocognitive mechanism for increased cooperation during group formation, Communications Psychology (2024). DOI: 10.1038/s44271-024-00177-3