Are religious people more generous than non-religious people? If so, are they more generous in general or mainly to members of their religious ingroup (i.e., parochially generous)? Also, do levels of parochial generosity differ between Christians, Muslims, and atheists? This paper examined these questions by using a novel design of the Dictator Game, where participants in multiple rounds decided how much money to keep for themselves and give to three other players, of whom some information is revealed. Three studies (N = 1,719) with a Swedish sample, an American sample, and a sample from Egypt and Lebanon were conducted. We found that religious people were more generous compared to non-religious people when information about players’ religious affiliation was available, but not when it was not available. The results suggest that if religious people are more generous, this mainly occurs when religious information is salient. We also found evidence of parochial generosity among Christians, Muslims, and atheists as all three groups gave more to their religious ingroup than to both of their outgroups. However, Muslims seemed to differ from Christians and atheists by giving more to their ingroup than the other two groups gave to their respective ingroups in the USA and possibly in Sweden.

We argue that people choosing prosocial distribution of goods (e.g., in dictator games) make this choice because they do not want to disappoint their partner rather than because of a direct preference for the chosen prosocial distribution. The chosen distribution is a means to fulfil one’s partner’s expectations. We review the economic experiments that corroborate this hypothesis and the experiments that deny that beliefs about others’ expectations motivate prosocial choice. We then formulate hypotheses about what types of expectation motivate someone to do what is expected: these are justifiable hopeful expectations that are clearly about his own choices. We experimentally investigate how people modulate their prosociality when they face low or unreasonably high expectations. In a version of a dictator game, we provide dictators with the opportunity to modulate their transfer as a function of their partner’s expectations. We observe that a significant portion of the population is willing to fulfil their partner’s expectation provided that this expectation expresses a reasonable hope. We conclude that people are averse to disappointing and we discuss what models of social preferences can account for the role of expectations in determining prosocial choice, with a special attention to models of guilt aversion and social esteem.

Understanding whether preferences are sensitive to the frame has been a major topic of debate in the last decades. For example, several works have explored whether the dictator game in the give frame gives rise to a different rate of pro-sociality than the same game in the take frame, leading to mixed results. Here we contribute to this debate with two experiments. In Study 1 (N=567) we implement an extreme dictator game in which the dictator either gets $0.50 and the recipient gets nothing, or the opposite (i.e., the recipient gets $0.50 and the dictator gets nothing). We experimentally manipulate the words describing the available actions using six terms, from very negative (e.g., stealing) to very positive (e.g., donating) connotations. We find that the rate of pro-sociality is affected by the words used to describe the available actions. In Study 2 (N=221) we ask brand new participants to rate each of the words used in Study 1 from “extremely wrong” to “extremely right”. We find that these moral judgments can explain the framing effect in Study 1. In sum, our studies provide evidence that framing effects in an extreme Dictator game can be generated using morally loaded language.

Is prosociality parochial or universalist? To shed light on this issue, we examine the relationship between the amount of money given to a stranger (giving in an incentivized Dictator Game) and intergroup attitudes and behavior in the context of randomly assigned teams (a minimal group paradigm) among N = 4,846 Amazon Mechanical Turk workers. Using a set of Dynamic Identity Diffusion Index measures, we find that participants who give more in the Dictator Game show less preferential identification with their team relative to the other team, and more identification with all participants regardless of team. Furthermore, in an incentivized Voter Game, participants who give more in the Dictator Game are more likely to support compromise by voting for the opposing team in order to avoid deadlock. Together, these results suggest that – at least in this subject pool and using these measures – prosociality is better characterized by universalism than parochialism.

Political identification is the basis of enduring conflict, suggesting thatpolitical attitudes are difficult to change. Here we show that in the 2016 U.S.Presidential Election, political identities underwent modification in responseto salient political events. We investigate these dynamics in detail bycollecting data at periodic intervals from mid-June 2016 through the generalelection (N = 3,958). We operationalize identification using prosocial giving inDictator Games played between supporters of competing primary candidatesrecruited from Amazon Mechanical Turk. The observed dynamics differed acrosspolitical parties. In-group bias among Democrats remained high until theDemocratic National Convention, disappeared shortly thereafter, and thenreturned during the final stage of the election. Bias among Republicans wasgenerally high until the final days of the election. The late resurgence of biasamong Democrats was not reflected in voting intentions, but may have presagedthe Democratic election loss.

This paper investigates how the numerosity bias influences individuals’ allocation of resources between themselves and others, using the backdrop of the traditional dictator game. Across four studies including both hypothetical and real exchanges of money, we show that the form of the numerical value representing the quantity of the resource (e.g., $20 vs 2000 cents) systematically biases the decision-maker to perceive the quantity s/he is thinking of allocating as being “less than adequate” or “more than adequate”. Essentially, such a biased perception of adequacy with respect to the quantity of the resource consequently influences the decision-maker’s final allocation decision. We attribute this systematic bias to the “numerosity” of the resource. We find that bigger numerical values representing quantity (e.g., 2000 cents) bias decision-makers to over-infer the quantity, thus inducing them to allocate less to the entities they are focusing on.

We test in the context of a dictator game the proposition that individuals may experience a self-control conflict between the temptation to act selfishly and the better judgment to act pro-socially. We manipulated the likelihood that individuals would identify self-control conflict, and we measured their trait ability to implement self-control strategies. Our analysis reveals a positive and significant correlation between trait self-control and pro-social behavior in the treatment where we expected a relatively high likelihood of conflict identification—but not in the treatment where we expected a low likelihood. The magnitude of the effect is of economic significance. We conclude that subtle cues might prove sufficient to alter individuals’ perception of allocation opportunities, thereby prompting individuals to draw on their own cognitive resources to act pro-socially.

In the face of economic inequalities, redistribution of wealth is a key debate for society, and understanding the reasons why individuals may support more or less redistribution can inform this debate. Here we investigate the mechanisms by which experiencing success in a task decreases the support for redistribution of the wealth generated by the task, such that overachievers favor less redistribution than underachievers. In a laboratory experiment, we replicate this effect and explore how it that may be mediatedby an in-group bias, or by changes in individuals’ principles of redistributive justice. Critically, both in-group favoritism and self-serving adjustments of justice principles partially accounted for the effect of status on redistribution choices. Our study thus sheds new light on the various ways by which economic experience affects support for redistribution.

We perform an experimental investigation using a dictator game in which individuals must make a moral decision — to give or not to give an amount of money to poor people in the Third World. A questionnaire in which the subjects are asked about the reasons for their decision shows that, at least in this case, moral motivations carry a heavy weight in the decision: the majority of dictators give the money for reasons of a consequentialist nature. Based on the results presented here and of other analogous experiments, we conclude that dicator behavior can be understood in terms of moral distance rather than social distance and that it systematically deviates from the egoism assumption in economic models and game theory.

In two studies, we tested the power of revenge as a justification mechanism thatenables people to cheat with a clear conscience. Specifically, we explored theeffects of prior dishonesty and unfairness towards participants on theirsubsequent moral behavior, as well as the physiological arousal associated withit. To this end, we employed a two-phase procedure. In the first phase,participants played one round of a bargaining game (the Ultimatum game in Study1 and the Dictator game in Study 2) in which we manipulated whether the playershad been treated (un)fairly and (dis)honestly by their opponent. In the secondphase, they did a perceptual task that allowed them to cheat for monetary gainat the expense of their opponent from the first phase. In Study 1, participantsalso took a lie detector test to assess whether their dishonesty in the secondphase could be detected. The behavioral results in both studies indicated thatthe opponent’s dishonesty was a stronger driver than theopponent’s unfairness for cheating as a form of retaliation. However, thephysiological arousal results suggest that feeling mistreated in general (andnot just cheated) allowed the participants to get revenge by cheating theoffender while dismissing their associated guilt feelings.

In this paper we investigate the effect of moral suasion on ingroup favouritism. We report a well-powered, pre-registered, two-stage 2x2 mixed-design experiment. In the first stage, groups are formed on the basis of how participants answer a set of questions, concerning non-morally relevant issues in one treatment (assorting on non-moral preferences), and morally relevant issues in another treatment (assorting on moral preferences). In the second stage, participants choose how to split a given amount of money between participants of their own group and participants of the other group, first in the baseline setting and then in a setting where they are told to do what they believe to be morally right (moral suasion). Our main results are: (i) in the baseline, participants tend to favour their own group to a greater extent when groups are assorted according to moral preferences, compared to when they are assorted according to non-moral preferences; (ii) the net effect of moral suasion is to decrease ingroup favouritism, but there is also a non-negligible proportion of participants for whom moral suasion increases ingroup favouritism; (iii) the effect of moral suasion is substantially stable across group assorting and four pre-registered individual characteristics (gender, political orientation, religiosity, pro-life vs pro-choice ethical convictions).

We report on three pre-registered studies testing whether people in the positionof describing a decision problem to decision-makers exploit this opportunity fortheir benefit, by choosing descriptions that may be potentially beneficial forthemselves. In Study 1, recipients of an extreme dictator game (where dictatorscan either take the whole pie for themselves or give it entirely to thereceiver) are asked to choose the instructions used to introduce the game todictators, from six different instructions known from previous research toaffect dictators’ decisions. The results demonstrate that some dictatorgame recipients tend to choose instructions that make them more likely toreceive a higher payoff. Study 2 shows that people who choose descriptions thatmake them more likely to receive a higher payoff indeed believe that they willreceive a higher payoff. Study 3 shows that receivers are more likely thandictators to choose these self-serving descriptions. In sum, our work suggeststhat some people choose descriptions that are beneficial to themselves; we alsofound some evidence that deliberative thinking and young age are associated withthis tendency.

The ultimatum and dictator games were developed to help identify the fundamental motivators of human behavior, typically by asking participants to share windfall endowments with other persons. In the ultimatum game, a common observation is that proposers offer, and responders refuse to accept, a much larger share of the endowment than is predicted by rational choice theory. However, in the real world, windfalls are rare: money is usually earned. I report here a small study aimed at testing how participants react to an ultimatum game after they have earned their endowments by either building a Lego model or spending some time sorting out screws by their length. I find that the shares that proposers offer and responders accept are significantly lower than that typically observed with windfall money, an observation that is intensified when the task undertaken to earn the endowment is generally less enjoyable and thus perhaps more effortful (i.e., screw sorting compared to Lego building). I suggest, therefore, that considerations of effort-based desert are often important drivers behind individual decision-making, and that laboratory experiments, if intended to inform public policy design and implementation, ought to mirror the broad characteristics of the realities that people face.

A sample of 641 participants were presented with four decision-making tasks during the first stages of the COVID–19 lockdown in Spain: The dictator game, framing problems, utilitarian/deontological and altruistic/egoistic moral dilemmas. Participants also completed questionnaires on mental health status and experiences related to the COVID–19 pandemic. We used boosted regression trees (an advanced form of regression analysis based on machine learning) to model relationships between responses to the questionnaires and decision-making tasks. Results showed that the psychological impact of the COVID–19 pandemic predicted participants’ responses to the framing problems and utilitarian/deontological and altruistic/egoistic moral dilemmas (but not to the dictator game). More concretely, the more psychological impact participants suffered, the more they were willing to choose the safest response in the framing problems, and the more deontological/altruistic were their responses to moral dilemmas. These results suggest that the psychological impact of the COVID–19 pandemic might prompt automatic processes.

According to Turnbull's 1972 ethnography The Mountain People, the Ik of Uganda had a culture of selfishness that made them uncooperative. His claims contrast with two widely accepted principles in evolutionary biology, that humans cooperate on larger scales than other species and that culture is an important facilitator of such cooperation. We use recently collected data to examine Ik culture and its influence on Ik behaviour. Turnbull's observations of selfishness were not necessarily inaccurate but they occurred during a severe famine. Cooperation re-emerged when people once again had enough resources to share. Accordingly, Ik donations in unframed Dictator Games are on par with average donations in Dictator Games played by people around the world. Furthermore, Ik culture includes traits that encourage sharing with those in need and a belief in supernatural punishment of selfishness. When these traits are used to frame Dictator Games, the average amounts given by Ik players increase. Turnbull's claim that the Ik have a culture of selfishness can be rejected. Cooperative norms are resilient, and the consensus among scholars that humans are remarkably cooperative and that human cooperation is supported by culture can remain intact.