Summary: A new study finds that people’s own behavior — not just the behavior of others or prevailing social norms — largely determines how they judge and respond to others in brief, zero-sum competitive situations.
Researchers report that generous individuals are more likely to reward generosity, while those who act selfishly are more likely to punish generous acts and favor selfish behavior, even when doing so reduces their own payoff. These results challenge the idea that social norms alone shape decision-making in competitive interactions and highlight reciprocity as a primary force guiding social expectations and evaluations.
Key Facts:
- An individual’s own generous or selfish choices influence how they evaluate others more strongly than the observed behaviors or attitudes of surrounding people.
- Generous people tend to reward generous actions; selfish people often punish generosity and accept or reward selfish actions, even at personal cost.
- The findings challenge prior assumptions that social norms are the predominant driver of decisions in competitive scenarios and point to reciprocity and self-referential evaluation as central mechanisms.
Source: University of Illinois
New research shows a person’s own behavior is the primary driver of how they treat others during short, zero-sum competitions. Generous people tend to reward generous behavior, while selfish individuals often punish generosity and reward selfishness—even when that harms their own outcomes.
The research, published in the journal Cognitive Science, indicates that people interpret others’ offers and intentions through the lens of how they themselves behave. In other words, evaluations of fairness, trustworthiness, and cooperation are filtered by one’s own past actions.
Paul Bogdan, a Ph.D. candidate at the University of Illinois Urbana-Champaign and lead author of the study, explains that earlier work emphasized social norms as the main basis for expectations: if people see selfish behavior around them, they come to accept selfishness as normal and adapt their behaviors accordingly. The current findings, however, show that individuals rely heavily on their own conduct when judging others.
To test these ideas, the team ran a series of behavioral experiments using economic games known to capture fairness and reciprocity, beginning with the Ultimatum Game. In this game, one player proposes how to split a fixed pot of money (for example, $10); the other player accepts or rejects the proposal. A rejection means neither player receives anything, so rejection operates as a costly form of punishment.
Participants alternated between the proposer and responder roles. Modeling of their expectations showed that people judged incoming offers relative to the offers they themselves had made. Generous players expected and accepted generous splits and rejected selfish ones, while selfish players were more willing to accept selfish offers and even rewarded selfish partners despite personal loss.
Additional experiments extended these observations to other paradigms, including a version of a public goods game and a trust game. Across tasks and cultural samples, participants preferred and trusted others who matched their own style of play — generous people trusted generous reciprocators, while selfish players trusted those who reciprocated selfish behavior. Observing selfishness in others only led to acceptance of selfishness when observers themselves began acting selfishly.
The researchers also reexamined data from a previous cross-cultural study that documented “antisocial punishment,” where individuals punish generosity. Their analysis supports the same conclusion: punishment choices were driven more by participants’ own behavior than by a desire to conform to local norms. When participants shifted from generosity to selfishness over time, their evaluations and punishments shifted too — but only after their own behavior changed.
These findings illuminate mechanisms behind social alignment: groups composed of predominantly selfish individuals may normalize selfishness because members evaluate others through their own behavior, encouraging newcomers to adopt similar strategies to belong. Conversely, groups with generous norms will reinforce generosity.
Florin Dolcos, a psychology professor who coauthored the study, notes that cultural norms do still matter, but they interact with a powerful self-referential process: people are not just passive observers of social environments; they interpret others’ actions in light of their own decisions and expectations.
Sanda Dolcos, another coauthor, emphasizes the broader implications. “This is not only a decision-making phenomenon,” she says. “It affects many kinds of social interactions and evaluations, from trust and cooperation to punishment and group dynamics.”
About this social neuroscience research news
Author: Diana Yates
Source: University of Illinois
Contact: Diana Yates – University of Illinois
Image: The image is credited to Neuroscience News
Original Research: Closed access. “Social expectations are primarily rooted in reciprocity: An investigation of fairness, cooperation and trustworthiness” by Paul Bogdan et al., Cognitive Science
Abstract
Social expectations are primarily rooted in reciprocity: An investigation of fairness, cooperation and trustworthiness
Social expectations guide how people evaluate others, but the origins of those expectations are debated. Traditional accounts emphasize learning from others: we form expectations based on what we observe in our environment and judge atypical actions harshly. In contrast, the reciprocity account holds that people evaluate others by comparing actions to their own choices, with expectations shaped by a drive to reciprocate.
Across four studies, the authors tested these competing views. Study 1 used an Ultimatum Game where participants switched between proposer and responder roles; modeling revealed that fairness judgments about offers were influenced by participants’ own offers. Study 2 replicated this pattern and showed that observing selfish offers only led to acceptance of selfishness when observers had begun to act selfishly themselves. Study 3 generalized these findings to the Public Goods Game, demonstrated cross-cultural robustness, and confirmed the occurrence of antisocial punishment by selfish players. Finally, Study 4 used the Trust Game to show that participants trusted partners who reciprocated their behavior—selfish or generous—at similar levels.
Together, these studies demonstrate that reciprocity and self-referential evaluation are central to social expectations, with implications for theories of decision-making and practical efforts to foster cooperation across diverse social settings.