Prosocial behavior can arise in response to top-down leadership, but a local individual who can exert positive influence within their community may hold even more sway. A paper in PNAS Nexus models the effectiveness of individuals to influence others for the good of society. (image: Romaoslo/istockphoto)

Getting individuals to act in the best interest of society can be a tricky balancing act, one that often walks a fine line between trying to convince people to act of their own volition, versus passing laws and regulations that make these actions compulsory. 

In a new paper, published in the journal PNAS Nexus, SFI External Professor Stefani Crabtree (Utah State University) and Science Board Fellow Simon Levin (Princeton University), together with Colin Wren (University of Colorado, Colorado Springs) and Avinash Dixit (Princeton), present both a mathematical model and an agent-based model that shows the effectiveness of influencers who convince others to make decisions in the best interest of society. This is in contrast to a more centralized model, where these actions are subject to laws and regulations, with an associated punishment for failing to comply. “In small societies, collective action can emerge from the bottom-up institution of social norms, which can be a more robust way to achieve success,” Levin says. “The question is how to achieve this at broader scales.” 

As their results suggest, the influence of individuals can play a valuable role in shaping the decisions of society, to the point where it can be almost equivalent to the effect of more centralized decisions, where these actions are subject to a centralized leader setting the tone via fear. In their model, the authors were able to show that if influential individuals are able to show a benefit for specific actions to others, this can influence others to do the same, which in turn can help shape society for the better.  

“This suggests that individual action can shape the way that society functions. By making decisions that have a personal benefit but also that benefit the group, we can achieve a more prosocial society,” says Crabtree. “While central decisions can be effective, our work shows that the influence of certain individuals can lead toward behaviors with a collective benefit.”

Some examples of these types of behaviors includes the decision of private individuals to donate their masks to healthcare workers at the start of the pandemic; the decision to replace water-intensive lawns with native landscaping that requires minimal irrigation in areas where water is scarce; or the decision to utilize carbon-neutral energy sources, such as installing solar panels. With these types of decisions, there is often a benefit both to the individual as well as society, whether it is ensuring the safety of healthcare workers, thus helping to ensure a functional healthcare system that can treat individuals during their own health crises; or saving money on utility bills, while also preserving the environment.  

With examples like these, although passing a law can enforce these actions, the influence of others can be almost as effective, while also encouraging a more cooperative sentiment among the individuals who choose to adopt these actions. “People get that positive feedback loop, when they see that if they cooperate, they benefit,” Crabtree says. 

Read the paper, “Influential Individuals Can Promote Prosocial Practices in Heterogeneous Societies: A Mathematical and Agent-Based Model” in PNAS Nexus (July 2, 2024). DOI: 10.1093/pnasnexus/pgae224 


Research was supported by an Army Research grant, the Masson-Marmot Fund for Archaeological Research, and the Coalition for Archaeological Synthesis.