The study addresses a long-standing puzzle in behavioural economics and psychology. Decades of research have established that people differ systematically in how much they weigh outcomes for themselves against outcomes for others, a dimension often described as social preferences. Yet people rarely face situations in which the consequences of their choices for others are perfectly transparent. Payoffs to interaction partners are frequently ambiguous, information is costly to acquire, and the causal chain between an action and its social footprint is murky. In those ambiguous spaces, the new findings indicate, both selfish and prosocial actors engage in a kind of motivated accounting, interpreting uncertain outcomes in ways that flatter their self-image.

The crucial asymmetry, however, lies in what happens next. When the researchers examined how these distortions travel between people, they found that distortions serving selfish motives catch on far more readily than distortions serving prosocial motives. In other words, if one person’s self-serving spin on an ambiguous social outcome makes selfish behaviour look acceptable, that interpretation can spread to observers and followers, who then adopt both the distorted belief and the selfish behaviour it licenses. Prosocial-serving distortions, by contrast, appear to be less contagious, meaning that the social dynamics of motivated reasoning are tilted in favour of selfishness.

This contagion effect has consequences that go beyond individual choices. If selfish-serving distortions propagate through groups, organisations, and markets, they can shift collective norms over time. A manager who convinces herself that a cost-saving measure probably will not harm employees, a trader who assumes that a risky product probably will not hurt clients, or a consumer who believes that a vaguely labelled product is probably ethical — each of these interpretations can be picked up, repeated, and amplified by others facing similar ambiguity. The result is a social environment in which self-serving beliefs about social impact become increasingly common, and in which followers become measurably more selfish as a consequence of adopting them.

The new work builds on a well-established experimental tradition. One of the foundational paradigms in this literature, introduced by Jason Dana and colleagues in 2007, demonstrated what the authors called exploiting moral wiggle room: when given the option to remain ignorant about how their choices affected a partner, many people chose ignorance and then behaved selfishly, revealing an illusory preference for fairness. People who claim to value equality will happily sacrifice it, provided they never have to see the inequality their choices create. The paradigm showed that information avoidance is not a passive failure but an active strategy for preserving a moral self-image while acting in one’s own interest.

Subsequent research has mapped the psychology of this strategy in detail. Eric Haisley and Robert Weber showed in 2010 that people interpret ambiguous payoff distributions in whatever way supports selfish choices, resolving uncertainty in the direction of their material interest. More recently, Rachel Carlson, Michal Maréchal, Bilal Oud, Ernst Fehr and Molly Crockett demonstrated motivated misremembering: after making selfish decisions, people recall those decisions as more generous than they actually were, with the memory distortion tracking the size of the selfish gain. Together, these findings sketch a mind that does not merely avoid inconvenient information but actively rewrites it — before, during, and after the decision.

What remained unclear until now was the social life of these distortions. Ignorance and spin are usually studied as individual phenomena, but people observe one another, imitate one another, and take cues from one another about what counts as acceptable behaviour. A 2026 study by Konstanze Reher, Maximilian Götz, Francesco Toscano and Julia Gross in the Journal of Experimental Social Psychology showed that both the social acceptance of ignoring social consequences and the choice to do so depend on how widespread ignorance already is. If many people around you are choosing not to know, ignoring the consequences of your own actions becomes more socially permissible and more individually likely. Information avoidance, in other words, is itself subject to social contagion.

The Vollberg and Gross study extends this logic from the avoidance of information to the distortion of it. The distinction matters because distortion is arguably the more insidious mechanism. A person who avoids information can at least claim not to have known; a person who distorts available information constructs a belief that actively supports a preferred course of action and can be communicated to others as if it were an honest assessment. When such communicated distortions are selfish-serving, they give observers both a template for interpreting ambiguity and a licence for selfishness. The new findings indicate that this template travels: followers exposed to selfish-serving distortions not only adopt the beliefs but also become more selfish in their own decisions, whereas prosocial-serving distortions do not exert a comparable pull.

The theoretical implications reach into one of the liveliest debates in economics. A major 2025 review by Ernst Fehr and Gary Charness in the Journal of Economic Literature synthesised the evidence on social preferences, documenting how robustly people differ in the weight they place on others’ outcomes and how consequential those differences are for markets, organisations, and policy. The new study adds a dynamic dimension to that picture. Social preferences are not only heterogeneous across individuals; the beliefs through which those preferences are expressed are malleable, motivated, and socially transmitted. A population’s apparent generosity or selfishness may therefore depend not just on the distribution of underlying preferences but on which kinds of motivated beliefs happen to be circulating within it.

For anyone concerned with institutional design, the practical message is sobering. Environments rich in ambiguity about social consequences do not merely permit individual self-serving behaviour; they cultivate and disseminate it. Transparency requirements, impact reporting, and mechanisms that make the distributional consequences of choices hard to misread are often justified on the grounds that they inform decision makers. The new research suggests a second justification: by reducing the interpretive space in which self-serving spin can operate, such mechanisms may also slow the social spread of the beliefs that normalise selfishness. Conversely, settings in which impact remains perpetually ambiguous may allow selfish-serving distortions to compound, generation after generation of decisions, quietly shifting what groups regard as acceptable. The fair-trade shopper, the policy maker, and the manager are all, in this light, participating in a collective negotiation over the meaning of uncertain consequences — and the evidence suggests that the selfish side of that negotiation currently has the easier job of winning converts.

Subject of Research: Motivated distortion of beliefs about the social consequences of one's actions and its contagious spread in social decision making

Article Title: Both selfish and prosocial actors distort their impact on others, but selfish-serving spin seems to spread

Article References: Both selfish and prosocial actors distort their impact on others, but selfish-serving spin seems to spread. (n.d.). https://doi.org/10.1038/s41562-026-02584-4

Image Credits: AI Generated

DOI: 10.1038/s41562-026-02584-4

Keywords: social preferences, decision making, behavioural economics, moral wiggle room, information avoidance, motivated reasoning, self-serving bias, prosociality, social contagion, human behaviour, ambiguity, cooperation