# How Reputation Systems Change the Psychological Antecedents of Fairness in Virtual Environments
## 1 Introduction
### Personal and Contextual Influences on Fairness and Adhesion to the Norm  
In the last 50 years, the idea of \"homo economics\" has been questioned by the scientific community, and the view of human beings as only dominated by personal interests is now considered outdated [7; 8]. Recent research expanded the knowledge of human sociality through simple and anonymous laboratory games [9], which provided evidence about fair behaviors, revealing that people usually do not pursue selfish interests (i.e., profits), but follow the norm of reciprocity, favoring fair interactions among individuals [10]. Social norms, like reciprocity and fairness, spread among human society thanks to the efforts of those who enforce such norms, support them even if it costs some fitness, for example, rewarding cooperative individuals and punishing uncooperative partners (i.e., altruistic punishment) [7; 10]. The concept of \"competitive altruism\" was developed to explain all the expensive behaviors that individuals perform for others' benefit [11]. Despite the initial cost that such behaviors imply, they appear to be convenient in the long-term, making cooperators more attractive partners for future interactions than uncooperative interactors [12]. A large number of economic studies (e.g., bargaining games, [13]) documented how pro-social norms play a central role in orienting players' behaviors, although altruistic acts can be risky and pricey [14]. A study by [PERSON], [PERSON], and [PERSON] [15], showed how both in an anonymous dictator and bargaining game, the participants tended to collaborate with the others, engaging in cooperative exchanges and fair divisions, rather than exploiting the context to get the full advantage. Context manipulation can influence the impact that social norms have on people's behavior. For instance, [PERSON] et al. [5] included a reputational system in a modified Ultimatum Game and investigated the effects that the social influence exerted by reputation, combined with specific personality traits and psychological characteristics, had on the players' conducts. Social dilemmas have been employed to investigate the effects of reputation on the achievement of collective goals. [PERSON] and [PERSON] [16] found that the participants' need to preserve a good reputation brought them to cooperate in a public good game, showing high levels of pro-social behavior. At the same time, when reputation was off the table, the players' contribution to the public good dropped to zero. Other studies corroborated such evidence, showing that individuals tended to be more cooperative when there was a chance to improve their reputation [16; 17; 18; 19; 20]. In a more recent study, the mere inclusion of a reputational system in a social dilemma context determined an increase of fair behaviors in those players who were not personally affected by reputation gain or loss [21]. Reputation mechanisms and their associated influence, change people's behavior, and affect the subjective perception of fairness [22; 23]. Social influence susceptibility, as well as norms compliance, appears to be mediated by situational (e.g., where the interaction occurs) and personal factors (e.g., psychological characteristics) [24]. As to the environmental part, the Social Identity Model of Deindividuation Effects (SIDE), demonstrated how certain peculiarities of the online scenario (i.e., anonymity, physical isolation, scarce identifiability, and social identity salience) determine higher levels of conformity to the local norms [25; 26]. Usually, reputation is built on social norms [27] and represents a social cue on which people rely to adapt their behavior (e.g., avoid cheaters) [28], thus representing a source of social influence. Combining the properties of the online environment with the influence exerted by reputation in an online social dilemma, it is more likely to observe higher levels of conformism to the norms of this specific context, and consequently to observe more pro-social behaviors [21].