arXiv subjects

Valerio Capraro

Publications and source records attributed to Valerio Capraro.

At least 55 records · Page 3Linked to original sources

arXiv2018

Low cognitive reflection predicts honesty for men but not for women

Previous experiments have explored the effects of gender and cognitive reflection on dishonesty separately. To the best of our knowledge, no studies have investigated potential interactions between these two factors. Exploring this interaction is important because previous work found that males tend to be both more deliberative than females. Therefore, it is possible that the gender effect on dishonesty is moderated by cognitive reflection. Here we report a large online experiment (N = 766) where subjects first have a chance to lie for their benefit and then take a Cognitive Reflection Test (CRT). We find a significant interaction between gender and CRT score such that lack of deliberation promotes honesty for men but not for women. Additional analyses highlight that this effect is mainly driven by men whose answers in the CRT are neither intuitive nor deliberative, who happen to be particularly honest in our deception game.

physics.soc-ph↗

arXiv2018

Grand challenges in social physics: In pursuit of moral behavior

Methods of statistical physics have proven valuable for studying the evolution of cooperation in social dilemma games. However, recent empirical research shows that cooperative behavior in social dilemmas is only one kind of a more general class of behavior, namely moral behavior, which includes reciprocity, respecting others' property, honesty, equity, efficiency, as well as many others. Inspired by these experimental works, we here open up the path towards studying other forms of moral behavior with methods of statistical physics. We argue that this is a far-reaching direction for future research that can help us answer fundamental questions about human sociality. Why did our societies evolve as they did? What moral principles are more likely to emerge? What happens when different moral principles clash? Can we predict the break out of moral conflicts in advance and contribute to their solution? These are amongst the most important questions of our time, and methods of statistical physics could lead to new insights and contribute towards finding answers.

physics.soc-ph↗

arXiv2018

Gender differences in lying in sender-receiver games: A meta-analysis

Whether there are gender differences in lying has been largely debated in the past decade. Previous studies found mixed results. To shed light on this topic, here I report a meta-analysis of 8,728 distinct observations, collected in 65 Sender-Receiver game treatments, by 14 research groups. Following previous work and theoretical considerations, I distinguish three types of lies: black lies, that benefit the liar at a cost for another person; altruistic white lies, that benefit another person at a cost for the liar; Pareto white lies, that benefit both the liar and another person. The results show that gender differences in lying significantly depend on the consequences of lying. Specifically: (i) males are significantly more likely than females to tell black lies (N=4,161); (ii) males are significantly more likely than females to tell altruistic white (N=2,940); (iii) results are inconclusive in the case of Pareto white lies (N=1,627).

physics.soc-ph↗

arXiv2018

Doing good vs. avoiding bad in prosocial choice: A refined test and extension of the morality preference hypothesis

Prosociality is fundamental to human social life, and, accordingly, much research has attempted to explain human prosocial behavior. Capraro and Rand (Judgment and Decision Making, 13, 99-111, 2018) recently provided experimental evidence that prosociality in anonymous, one-shot interactions (such as Prisoner's Dilemma and Dictator Game experiments) is not driven by outcome-based social preferences - as classically assumed - but by a generalized morality preference for "doing the right thing". Here we argue that the key experiments reported in Capraro and Rand (2018) comprise prominent methodological confounds and open questions that bear on influential psychological theory. Specifically, their design confounds: (i) preferences for efficiency with self-interest; and (ii) preferences for action with preferences for morality. Furthermore, their design fails to dissociate the preference to do "good" from the preference to avoid doing "bad". We thus designed and conducted a preregistered, refined and extended test of the morality preference hypothesis (N=801). Consistent with this hypothesis, our findings indicate that prosociality in the anonymous, one-shot Dictator Game is driven by preferences for doing the morally right thing. Inconsistent with influential psychological theory, however, our results suggest the preference to do "good" was as potent as the preference to avoid doing "bad" in this case.

physics.soc-ph↗

arXiv2018

Women are slightly more cooperative than men (in one-shot Prisoner's dilemma games played online)

Differences between men and women have intrigued generations of social scientists, who have found that the two sexes behave differently in settings requiring competition, risk taking, altruism, honesty, as well as many others. Yet, little is known about whether there are gender differences in cooperative behavior. Previous evidence is mixed and inconclusive. Here I shed light on this topic by analyzing the totality of studies that my research group has conducted since 2013. This is a dataset of 10,951 observations coming from 7,322 men and women living in the US, recruited through Amazon Mechanical Turk, and who passed four comprehension questions to make sure they understand the cooperation problem (a one-shot prisoner's dilemma). The analysis demonstrates that women are more cooperative than men. The effect size is small (about 4 percentage points, and this might explain why previous studies failed to detect it) but highly significant (p<.0001).

physics.soc-ph↗

arXiv2018

Social versus Moral preferences in the Ultimatum Game: A theoretical model and an experiment

In the Ultimatum Game (UG) one player, named "proposer", has to decide how to allocate a certain amount of money between herself and a "responder". If the offer is greater than or equal to the responder's minimum acceptable offer (MAO), then the money is split as proposed, otherwise, neither the proposer nor the responder get anything. The UG has intrigued generations of behavioral scientists because people in experiments blatantly violate the equilibrium predictions that self-interested proposers offer the minimum available non-zero amount, and self-interested responders accept. Why are these predictions violated? Previous research has mainly focused on the role of social preferences. Little is known about the role of general moral preferences for doing the right thing, preferences that have been shown to play a major role in other social interactions (e.g., Dictator Game and Prisoner's Dilemma). Here I develop a theoretical model and an experiment designed to pit social preferences against moral preferences. I find that, although people recognize that offering half and rejecting low offers are the morally right things to do, moral preferences have no causal impact on UG behavior. The experimental data are indeed well fit by a model according to which: (i) high UG offers are motivated by inequity aversion and, to a lesser extent, self-interest; (ii) high MAOs are motivated by inequity aversion.

physics.soc-ph↗

arXiv2018

Hierarchical invasion of cooperation in complex networks

The emergence and survival of cooperation is one of the hardest problems still open in science. Several factors such as the existence of punishment, fluctuations in finite systems, repeated interactions and the formation of prestige may all contribute to explain the counter-intuitive prevalence of cooperation in natural and social systems. The characteristics of the interaction networks have been also signaled as an element favoring the persistence of cooperators. Here we consider the invasion dynamics of cooperative behaviors in complex topologies. The invasion of a heterogeneous network fully occupied by defectors is performed starting from nodes with a given number of connections (degree) $k_0$. The system is then evolved within a Prisoner's Dilemma game and the outcome is analyzed as a function of $k_0$ and the degree $k$ of the nodes adopting cooperation. Carried out using both numerical and analytical approaches, our results show that the invasion proceeds following preferentially a hierarchical order in the nodes from those with higher degree to those with lower degree. However, the invasion of cooperation will succeed only when the initial cooperators are numerous enough to form a cluster from which cooperation can spread. This implies that the initial condition must be a suitable equilibrium between high degree and high numerosity, which usually takes place, when possible, at intermediate values of $k_0$. These findings have potential applications, as they suggest that, in order to promote cooperative behavior on complex networks, one should infect with cooperators \emph{high but not too high} degree nodes.

physics.soc-ph↗

arXiv2017

Does the truth come naturally? Time pressure increases honesty in one-shot deception games

Many situations require people to act quickly and are characterized by asymmetric information. Since asymmetric information makes people tempted to misreport their private information for their own benefit, it is of primary importance to understand whether time pressure affects honest behavior. A theory of social heuristics (the Social Heuristics Hypothesis, SHH), predicts that, in case of one-shot interactions, such an effect exists and it is positive. The SHH proposes that when people have no time to evaluate all available alternatives, they tend to rely on heuristics, choices that are optimal in everyday, repeated interactions and that have been internalized over time; and then, after deliberation, people shift their behavior towards the one that is optimal in the given interaction. Thus, the SHH predicts that time pressure increases honesty in one-shot interactions (because honesty may be optimal in repeated interactions, while dishonesty is always optimal in the short run). However, to the best of our knowledge, no experimental studies have tested this prediction. Here, I report a large (N=1,013) study aimed at filling this gap. In this study, participants were given a private information and were asked to report it within 5 seconds vs after 30 seconds. The interaction was one-shot, and payoffs were such that subjects had an incentive to lie. As predicted by the SHH, I find that time pressure increases honest behavior. In doing so, these results provide new insights on the role of time pressure on honesty, and provide one more piece of evidence in support of the Social Heuristics Hypothesis.

physics.soc-ph↗

arXiv2017

Deliberation favours social efficiency by making people disregard their relative shares: Evidence from US and India

Groups make decisions on both the production and the distribution of resources. These decisions typically involve a tension between increasing the total level of group resources (i.e. social efficiency) and distributing these resources among group members (i.e. individuals' relative shares). This is the case because the redistribution process may destroy part of the resources, thus resulting in socially inefficient allocations. Here we apply a dual-process approach to understand the cognitive underpinnings of this fundamental tension. We conducted a set of experiments to examine the extent to which different allocation decisions respond to intuition or deliberation. In a newly developed approach, we assess intuition and deliberation at both the trait level (using the Cognitive Reflection Test, henceforth CRT) and the state level (through the experimental manipulation of response times). To test for robustness, experiments were conducted in two countries: the US and India. Despite absolute level differences across countries, in both locations we show that: (i) time pressure and low CRT scores are associated with individuals' concerns for their relative shares; (ii) time delay and high CRT scores are associated with individuals' concerns for social efficiency. These findings demonstrate that deliberation favours social efficiency by overriding individuals' intuitive tendency to focus on relative shares.

physics.soc-ph↗

arXiv2016

Partner selection supported by opaque reputation promotes cooperative behavior

Reputation plays a major role in human societies, and it has been proposed as an explanation for the evolution of cooperation. While the majority of previous studies equates reputation with a transparent and complete history of players' past decisions, in real life, reputations are often ambiguous and opaque. Using web-based experiments, we explore the extent to which opaque reputation works in isolating defectors, with and without partner selection opportunities. Our results show that low reputation works as a signal of untrustworthiness, whereas medium or high reputation are not taken into account by participants for orienting their choices. We also find that reputation without partner selection does not promote cooperative behavior; that is, defectors do not turn into cooperators only for the sake of getting a positive reputation. Finally, in a third study, we find that, when reputation is pivotal to selection, then a substantial proportion of would-be-defectors turn into cooperators. Taken together, these results provide insights on the characteristics of reputation and on the way in which humans make use of it when selecting partners but also when knowing that they will be selected.

physics.soc-ph↗

arXiv2016

Translucent Players: Explaining Cooperative Behavior in Social Dilemmas

In the last few decades, numerous experiments have shown that humans do not always behave so as to maximize their material payoff. Cooperative behavior when non-cooperation is a dominant strategy (with respect to the material payoffs) is particularly puzzling. Here we propose a novel approach to explain cooperation, assuming what Halpern and Pass call translucent players. Typically, players are assumed to be opaque, in the sense that a deviation by one player in a normal-form game does not affect the strategies used by other players. But a player may believe that if he switches from one strategy to another, the fact that he chooses to switch may be visible to the other players. For example, if he chooses to defect in Prisoner's Dilemma, the other player may sense his guilt. We show that by assuming translucent players, we can recover many of the regularities observed in human behavior in well-studied games such as Prisoner's Dilemma, Traveler's Dilemma, Bertrand Competition, and the Public Goods game.

cs.GT↗

arXiv2016

Gender differences in altruism: Expectations, actual behaviour and accuracy of beliefs

Previous research shows that women are more altruist than men in dictator game experiments. Yet, little is known whether women are expected to be more altruist than men. Here we elicit third-parties' beliefs about dictators' donations conditional on knowing the gender of the dictator. Our data provide evidence of three main findings: (i) women are expected to be more altruist than men; (ii) both men and women have correct beliefs about the level of altruism among men; and (iii) both men and women overestimate the level of altruism among women. In doing so, our results uncover a perception gap according to which, although women are more altruist than men, they are expected to be even more altruist than they actually are.

physics.soc-ph↗

arXiv2016

To know or not to know? How looking at payoffs signals selfish behavior

In daily life, subjects often face a social dilemma in two stages. In Stage 1, they recognize the social dilemma structure of the decision problem at hand (a tension between personal interest and collective interest); in Stage 2, they have to choose between gathering additional information to learn the exact payoffs corresponding to each of the two options or making a choice without looking at the payoffs. While previous theoretical research suggests that the mere act of considering one's strategic options in a social dilemma will be met with distrust, no experimental study has tested this hypothesis. What does "looking at payoffs" signal in observers? Do observers' beliefs actually match decision makers' intentions? Experiment 1 shows that the actual action of looking at payoffs signals selfish behavior, but it does not actually mean so. Experiments 2 and 3 show that, when the action of looking at payoffs is replaced by a self-report question asking the extent to which participants look at payoffs in their everyday lives, subjects in high looking mode are indeed more selfish than those in low looking mode, and this is correctly predicted by observers. These results support Rand and colleagues' Social Heuristics Hypothesis and the novel "cooperate without looking" model by Yoeli, Hoffman, and Nowak. However, Experiment 1 shows that actual looking may lead to different results, possibly caused by the emergence of a moral cleansing effect.

q-bio.PE↗

arXiv2015

On the axiomatization of convex subsets of Banach spaces

We prove that any convex-like structure in the sense of Nate Brown is affinely and isometrically isomorphic to a closed convex subset of a Banach space. This answers an open question of Brown. As an intermediate step, we identify Brown's algebraic axioms as equivalent to certain well-known axioms of abstract convexity. We conclude with a new characterization of convex subsets of Banach spaces.

math.MG↗

arXiv2015

Does telling white lies signal pro-social preferences?

The opportunity to tell a white lie (i.e., a lie that benefits another person) generates a moral conflict between two opposite moral dictates, one pushing towards telling always the truth and the other pushing towards helping others. Here we study how people resolve this moral conflict. What does telling a white lie signal about a person's pro-social tendencies? To answer this question, we conducted a two-stage 2x2 experiment. In the first stage, we used a Deception Game to measure aversion to telling a Pareto white lie (i.e., a lie that helps both the liar and the listener), and aversion to telling an altruistic white lie (i.e., a lie that helps the listener at the expense of the liar). In the second stage we measured altruistic tendencies using a Dictator Game and cooperative tendencies using a Prisoner's dilemma. We found three major results: (i) both altruism and cooperation are positively correlated with aversion to telling a Pareto white lie; (ii) both altruism and cooperation are negatively correlated with aversion to telling an altruistic white lie; (iii) men are more likely than women to tell an altruistic white lie, but not to tell a Pareto white lie. Our results shed light on the moral conflit between pro-sociality and truth-telling. In particular, the first finding suggests that a significant proportion of people have non-distributional notions of what the right thing to do is: irrespective of their economic consequences, they tell the truth, they cooperate, they share their money.

physics.soc-ph↗

arXiv2015

Cooperative Equilibrium beyond Social Dilemmas: Pareto Solvable Games

A recently introduced concept of "cooperative equilibrium", based on the assumption that players have a natural attitude to cooperation, has been proven a powerful tool in predicting human behaviour in social dilemmas. In this paper, we extend this idea to more general game models, termed "Pareto solvable" games, which in particular include the Nash Bargaining Problem and the Ultimatum Game. We show that games in this class possess a unique pure cooperative equilibrium. Furthermore, for the Ultimatum Game, this notion appears to be strongly correlated with a suitably defined variant of the Dictator Game. We support this observation with the results of a behavioural experiment conducted using Amazon Mechanical Turk, which demonstrates that our approach allows for making statistically precise predictions of average behaviour in such settings.

cs.GT↗

arXiv2015

Group size effect on cooperation in one-shot social dilemmas II. Curvilinear effect

In a world in which many pressing global issues require large scale cooperation, understanding the group size effect on cooperative behavior is a topic of central importance. Yet, the nature of this effect remains largely unknown, with lab experiments insisting that it is either positive or negative or null, and field experiments suggesting that it is instead curvilinear. Here we shed light on this apparent contradiction by considering a novel class of public goods games inspired to the realistic scenario in which the natural output limits of the public good imply that the benefit of cooperation increases fast for early contributions and then decelerates. We report on a large lab experiment providing evidence that, in this case, group size has a curvilinear effect on cooperation, according to which intermediate-size groups cooperate more than smaller groups and more than larger groups. In doing so, our findings help fill the gap between lab experiments and field experiments and suggest concrete ways to promote large scale cooperation among people.

q-bio.PE↗

arXiv2015

Social setting, intuition, and experience in lab experiments interact to shape cooperative decision-making

Recent studies suggest that cooperative decision-making in one-shot interactions is a history-dependent dynamic process: promoting intuition versus deliberation has typically a positive effect on cooperation (dynamism) among people living in a cooperative setting and with no previous experience in economic games on cooperation (history-dependence). Here we report on a lab experiment exploring how these findings transfer to a non-cooperative setting. We find two major results: (i) promoting intuition versus deliberation has no effect on cooperative behavior among inexperienced subjects living in a non-cooperative setting; (ii) experienced subjects cooperate more than inexperienced subjects, but only under time pressure. These results suggest that cooperation is a learning process, rather than an instinctive impulse or a self-controlled choice, and that experience operates primarily via the channel of intuition. In doing so, our findings shed further light on the cognitive basis of human cooperative decision-making and provide further support for the recently proposed Social Heuristics Hypothesis.

q-bio.PE↗