A new study published in the Proceedings of the National Academy of Sciences (PNAS) challenges long-held assumptions about human cooperation. Traditionally, behavioral scientists and economists have primarily studied cooperation in public good contexts through repeated interactions, where individuals can build trust and reciprocal relationships, adjusting their behavior based on the actions of others. However, many real-world, naturally occurring situations, such as volunteering or donating to crisis relief efforts, are one-time decisions with no obvious future interactions or relationships to consider. This new study, co-authored by Dr. Natalie Struwe and Prof. Esther Blanco from the University of Innsbruck with Prof. James Walker from Indiana University, explored how individuals cooperate when they only have one opportunity to cooperate in a social group, not knowing the identity of other group members.
Two large-scale experiments
Across two experiments involving over 2,000 participants, the researchers varied the potential benefits from cooperation in public good provision. Despite the increased benefits for cooperating, the study found no significant change in how much individuals were willing to cooperate. The mechanism behind this behavior seems to lie in individuals' expectations of others’ willingness to cooperate which were also not found to vary with the benefits of cooperating. As participants did not expect others to cooperate more when benefits increased, they were unlikely to increase their own cooperation efforts—even when the benefits of cooperation doubled.
"Our findings highlight a critical gap in our understanding of cooperative behavior in single-encounter settings," said Dr. Natalie Struwe of the Department of Public Finance at the University of Innsbruck. "The decision to cooperate is characterized by what we call a social dilemma. These are situations where self-interest is in conflict with social interests. With higher benefits from cooperation, however, this conflict is much lower and we would expect to see much higher cooperation rates. But, we were surprised to see that even when we dramatically increased the benefits from cooperation, people’s cooperation efforts did not rise accordingly. This suggests that real-world cooperation—such as donating to immediate disaster relief—may not always be driven by an assessment of increased benefits."
Consistent results across data collections
“We couldn’t believe the results ourselves at first, double-checked the data several times, and repeated the study with several populations,“ said Professor Esther Blanco of the Department of Public Finance at the University of Innsbruck. “In the end, we gathered nearly 2,000 data points, conducting experiments online with the general population from the UK, as well as with our students—both online and in our laboratory. No matter what we did, the results remained consistent: cooperation levels were remarkably stable. The general public was no more or less cooperative than our students. On average, participants were willing to invest around 40% of their available money to boost their group’s earnings, regardless of the specific setting."
"Spontaneous cooperation in one-time situations is more common than we might think," Professor James Walker, another of the co-authors, at the Department of Economics of Indiana University, explained. "For example, people coming together to provide immediate disaster relief is a case of one-time cooperation, where individuals decide to act and help without knowing whether they will interact with the same people again."
The study's results have important implications for how we think about encouraging cooperation in public good provision, especially in urgent, one-time scenarios like disaster relief or emergency volunteering. It also points to the need to better understand the fundamentals of cooperative behavior, one of the most defining characteristics of humankind.
Key Findings:
- Individuals do not significantly change their contributions to public goods when the benefits from cooperation increase, in contrast to previous research in repeated interactions.
- Expectations about others’ contributions strongly influence individual behavior in one-time settings and do not vary significantly with changes in benefits from cooperation.
- Average cooperation levels remained consistently around 40% across different participant groups and experimental settings, including both the general public and university students.
- The study underscores the need for further research into cooperation in one-time decision settings, in particular how individuals interpret the benefits and respond in such settings, as well as how they expect others to respond.
This research opens new avenues for exploring how to effectively foster cooperation in critical single encounter situations and calls for a deeper understanding of the psychological and social factors at play.
Paper:
Natalie Struwe, Esther Blanco, James M. Walker: Increasing benefits in one-time public goods does not promote cooperation, Proceedings of the National Academy of Sciences 2024, Vol. 121, No 41, DOI: 10.1073/pnas.2410326121, https://www.pnas.org/doi/abs/10.1073/pnas.2410326121