Tit for tat
Testosterone Inhibits Trust but Promotes Reciprocity
Maarten Boksem et al.
Psychological Science, forthcoming
Abstract:
The steroid hormone testosterone has been associated with behavior intended to obtain or maintain high social status. Although such behavior is typically characterized as aggressive and competitive, it is clear that high social status is achieved and maintained not only through antisocial behavior but also through prosocial behavior. In the present experiment, we investigated the impact of testosterone administration on trust and reciprocity using a double-blind randomized control design. We found that a single dose of 0.5 mg of testosterone decreased trust but increased generosity when repaying trust. These findings suggest that testosterone may mediate different types of status-seeking behavior. It may increase competitive, potentially aggressive, and antisocial behavior when social challenges and threats (i.e., abuse of trust and betrayal) need to be considered; however, it may promote prosocial behavior in the absence of these threats, when high status and good reputation may be best served by prosocial behavior.
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Money and trust among strangers
Gabriele Camera, Marco Casari & Maria Bigoni
Proceedings of the National Academy of Sciences, 10 September 2013, Pages 14889-14893
Abstract:
What makes money essential for the functioning of modern society? Through an experiment, we present evidence for the existence of a relevant behavioral dimension in addition to the standard theoretical arguments. Subjects faced repeated opportunities to help an anonymous counterpart who changed over time. Cooperation required trusting that help given to a stranger today would be returned by a stranger in the future. Cooperation levels declined when going from small to large groups of strangers, even if monitoring and payoffs from cooperation were invariant to group size. We then introduced intrinsically worthless tokens. Tokens endogenously became money: subjects took to reward help with a token and to demand a token in exchange for help. Subjects trusted that strangers would return help for a token. Cooperation levels remained stable as the groups grew larger. In all conditions, full cooperation was possible through a social norm of decentralized enforcement, without using tokens. This turned out to be especially demanding in large groups. Lack of trust among strangers thus made money behaviorally essential. To explain these results, we developed an evolutionary model. When behavior in society is heterogeneous, cooperation collapses without tokens. In contrast, the use of tokens makes cooperation evolutionarily stable.
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Predictors of hazing motivation in a representative sample of the United States
Aldo Cimino
Evolution and Human Behavior, forthcoming
Abstract:
Hazing - the abuse of new or prospective group members - remains a puzzling and persistent cross-cultural phenomenon. Aspects of hazing behavior may reflect the operation of psychological adaptations designed to lessen certain forms of ancestral coalitional exploitation. Using a representative sample of the United States, this paper replicates and extends prior findings on predictors of hazing motivation in a university population. Results suggest that probable vectors of ancestral exploitation by newcomers (e.g., freely available group benefits) predict desired hazing severity, and that these effects generalize to a larger and more diverse sample. Findings are discussed in light of hazing's evident complexity and cultural patterning.
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Can you trust the good guys? Trust within and between groups with different missions
Sebastian Fehrler & Michael Kosfeld
Economics Letters, forthcoming
Abstract:
NGOs and other non-profit organizations attract workers who strongly identify themselves with their missions. We study whether these "good guys" are more trustworthy and how such pronounced group identities affect trust and trustworthiness within the groups and toward out-groups. We find that subjects who strongly identify themselves with a non-profit mission are more trustworthy in a minimal group setting but also harshly discriminate against out-groups when subjects are grouped by the missions they identify themselves with.
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Is cooperativeness readable in static facial features? An inter-cultural approach
Arnaud Tognetti et al.
Evolution and Human Behavior, forthcoming
Abstract:
There is evidence in the literature that non-verbal physical features are used as cues for a propensity to cooperate. However, further studies of the human ability to visually detect cooperativeness are required. In particular, the existence of static facial cues of altruism remains questionable. Moreover, an investigation of both sex differences and cross-cultural applicability with respect to altruism detection skills is crucial in the context of the evolution of human cooperation. In this study, we used both a public good game and a charitable contribution to assess the cooperativeness of 156 men and 172 women in rural Senegal and took facial photographs of these individuals. The second portion of the study was conducted in France. In total, 194 men and 171 women were asked to distinguish the most and least selfish individual from a series of 80 pairs of Senegalese facial photographs, each pair consisting of the highest and the lowest contributor from a group in the public good game. Using mixed modeling techniques, we controlled for facial masculinity, age and socio-economic status. For male pairs, both male and female French raters were able to identify more often than by chance which individual made the smallest contribution to the public good in each group; however, detection was not successful with female faces. These results suggest that sex-specific traits are involved and that only male facial traits indicating cooperative skills are, at least inter-culturally, readable. The specific facial traits involved are investigated. However, the charitable contribution was not correlated with the contribution to the public good, and further work is necessary to identify which specific altruistic traits are detectable and to assess the generality of these results.
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I'm Sorry About the Rain! Superfluous Apologies Demonstrate Empathic Concern and Increase Trust
Alison Wood Brooks, Hengchen Dai & Maurice Schweitzer
Social Psychological and Personality Science, forthcoming
Abstract:
Existing apology research has conceptualized apologies as a device to rebuild relationships following a transgression. Individuals, however, often apologize for circumstances for which they are obviously not culpable (e.g., heavy traffic or bad weather). In this article, we define superfluous apologies as expressions of regret for an undesirable circumstance for which the apologizer is clearly not responsible. Across four studies, we find that superfluous apologies increase trust in the apologizer. This effect is mediated by empathic concern. Issuing a superfluous apology demonstrates empathic concern for the victim and increases the victim's trust in the apologizer.
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Who Cries Wolf, and When? Manipulation of Perceived Threats to Preserve Rank in Cooperative Groups
Pat Barclay & Stephen Benard
PLoS ONE, September 2013
Abstract:
People perform greater within-group cooperation when their groups face external threats, such as hostile outgroups or natural disasters. Researchers and social commentators suggest that high-ranking group members manipulate this "threat-dependent" cooperation by exaggerating threats in order to promote cooperation and suppress competition for their position. However, little systematic research tests this claim or possible situational moderators. In three studies, we use a cooperative group game to show that participants pay to increase others' perceptions of group threats, and spend more on manipulation when holding privileged positions. This manipulation cost-effectively elicits cooperation and sustains privilege, and is fostered by competition over position, not only position per se. Less cooperative people do more manipulation than more cooperative people do. Furthermore, these effects generalize to broader definitions of privilege. Conceptually, these results offer new insights into an understudied dimension of group behavior. Methodologically, the research extends cooperative group games to allow for analyzing more complex group dynamics.
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Convergence of speech rate in conversation predicts cooperation
Joseph Manson et al.
Evolution and Human Behavior, forthcoming
Abstract:
During conversation, interlocutors coordinate their behavior on many levels. Two distinct forms of behavioral coordination have been empirically linked with affiliation and cooperation during or following face-to-face interaction: behavior matching and interpersonal synchrony. Only the latter form constitutes behavioral entrainment involving a coupling between independent oscillators. We present the first study of the association between spontaneously occurring behavioral coordination and post-interaction economic game play. Triads of same-sexed strangers conversed for 10 min, after which each participant played an unannounced one-shot prisoner's dilemma (PD) toward each co-participant. When dyads had higher language style matching scores (LSM: Gonzales, A.L., Hancock, J.T., & Pennebaker, J.W. (2010). Language style matching as a predictor of social dynamics in small groups. Communication Research, 31, 3-19), the individuals evaluated each other more positively, but they were no more likely to cooperate in the PD. However, when dyads' speech rates (mean syllable duration) converged more strongly from the beginning to the end of the conversation, they were more likely to cooperate in the PD, despite no effect on interpersonal evaluations. Speech rate convergence, a form of rhythmic entrainment, could benefit interlocutors by mutually reducing cognitive processing during interaction. We suggest that spontaneous, temporally based behavioral coordination might facilitate prosocial behavior when the joint cooperative effort is itself perceived as a form of coordination.
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James Rilling et al.
Psychoneuroendocrinology, forthcoming
Abstract:
Both oxytocin (OT) and vasopressin (AVP) are known to modulate social behavior, and dysfunction in both systems has been postulated as a potential cause of certain psychiatric disorders that involve social behavioral deficits. In particular, there is growing interest in intranasal OT as a potential treatment for certain psychiatric disorders, and preliminary pre-clinical and clinical studies suggest efficacy in alleviating some of the associated symptoms. However, the vast majority of research participants in these studies have been male, and there is evidence for sexually differentiated effects of nonapeptides in both humans and non-human animals. To date, no study has investigated the effect of intranasal OT on brain function in human males and females within the same paradigm. Previously, in a randomized, placebo-controlled, double-blind fMRI study, we reported effects of intranasal OT and AVP on behavior and brain activity of human males as they played an interactive social game known as the Prisoner's Dilemma Game. Here, we present findings from an identical study in human females, and compare these with our findings from males. Overall, we find that both behavioral and neural responses to intranasal OT and AVP are highly sexually differentiated. In women, AVP increased conciliatory behavior, and both OT and AVP caused women to treat computer partners more like humans. In men, AVP increased reciprocation of cooperation from both human and computer partners. However, no specific drug effects on behavior were shared between men and women. During cooperative interactions, both OT and AVP increased brain activity in men within areas rich in OT and AVP receptors and in areas playing a key role in reward, social bonding, arousal and memory (e.g., the striatum, basal forebrain, insula, amygdala and hippocampus), whereas OT and AVP either had no effect or in some cases actually decreased brain activity in these regions in women. OT treatment rendered neural responses of males more similar to responses of females in the placebo group and vice-versa, raising the prospect of an inverted u-shaped dose response to central OT levels. These findings emphasize the need to fully characterize the effects of intranasal OT and AVP in both males and females and at multiple doses before widespread clinical application will be warranted.
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Lying about What You Know or about What You Do?
Marta Serra-Garcia, Eric van Damme & Jan Potters
Journal of the European Economic Association, October 2013, Pages 1204-1229
Abstract:
We compare communication about private information to communication about actions in a one-shot 2-person public good game with private information. The informed player, who knows the exact return from contributing and whose contribution is unobserved, can send a message about the return or her contribution. Theoretically, messages can elicit the uninformed player's contribution, and allow the informed player to free-ride. The exact language used is not expected to matter. Experimentally, however, we find that free-ride depends on the language: the informed player free-rides less - and thereby lies less frequently - when she talks about her contribution than when she talks about the return. Further experimental evidence indicates that it is the promise component in messages about the contribution that leads to less free-ride and less lying.
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Resounding Silences: Subtle Norm Regulation in Everyday Interactions
Namkje Koudenburg, Tom Postmes & Ernestine Gordijn
Social Psychology Quarterly, September 2013, Pages 224-241
Abstract:
In this article we suggest a mechanism for norm regulation that does not rely on explicit information exchange or costly reinforcement, but rather on the sensitivity of group members to social cues in their environment. We examine whether brief conversational silences can (a) signal a threat to one's inclusionary status in the group and (b) motivate people to shift their attitudes to be in line with group norms. In two experiments - using videotaped and actual conversations, respectively - we manipulated the presence of a brief silence after group members expressed a certain attitude. As predicted, attitudes changed relative to the norm after such a brief silence. Those highly motivated to belong changed their attitude to become more normative, whereas those less motivated to belong shifted away from the group norm. The results suggest that social regulation may occur through very subtle means.
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Self-Organization for Collective Action: An Experimental Study of Voting on Sanction Regimes
Thomas Markussen, Louis Putterman & Jean-Robert Tyran
Review of Economic Studies, forthcoming
Abstract:
Entrusting the power to punish to a central authority is a hallmark of civilization, yet informal or horizontal sanctions have attracted more attention of late. We study experimentally a collective action dilemma and test whether subjects choose a formal sanction scheme that costs less than the surplus it makes possible, as predicted by standard economic theory, or instead opt for the use of informal sanctions or no sanctions. Our subjects choose, and succeed in using, informal sanctions surprisingly often, their voting decisions being responsive to the cost of formal sanctions. Adoption by voting enhances the efficiency of both informal sanctions and non-deterrent formal sanctions. Results are qualitatively confirmed under several permutations of the experimental design.
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From extortion to generosity, evolution in the Iterated Prisoner's Dilemma
Alexander Stewart & Joshua Plotkin
Proceedings of the National Academy of Sciences, 17 September 2013, Pages 15348-15353
Abstract:
Recent work has revealed a new class of "zero-determinant" (ZD) strategies for iterated, two-player games. ZD strategies allow a player to unilaterally enforce a linear relationship between her score and her opponent's score, and thus to achieve an unusual degree of control over both players' long-term payoffs. Although originally conceived in the context of classical two-player game theory, ZD strategies also have consequences in evolving populations of players. Here, we explore the evolutionary prospects for ZD strategies in the Iterated Prisoner's Dilemma (IPD). Several recent studies have focused on the evolution of "extortion strategies," a subset of ZD strategies, and have found them to be unsuccessful in populations. Nevertheless, we identify a different subset of ZD strategies, called "generous ZD strategies," that forgive defecting opponents but nonetheless dominate in evolving populations. For all but the smallest population sizes, generous ZD strategies are not only robust to being replaced by other strategies but can selectively replace any noncooperative ZD strategy. Generous strategies can be generalized beyond the space of ZD strategies, and they remain robust to invasion. When evolution occurs on the full set of all IPD strategies, selection disproportionately favors these generous strategies. In some regimes, generous strategies outperform even the most successful of the well-known IPD strategies, including win-stay-lose-shift.
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On the Acceptance of Apologies
Urs Fischbacher & Verena Utikal
Games and Economic Behavior, forthcoming
Abstract:
An apology is a strong and cheap device to restore social or economic relationships that have been disturbed. In a laboratory experiment in which apologies emerge endogenously, we find that harmdoers use apologies in particular if they fear punishment and if their intentions cannot be easily inferred. After offenses with ambiguous intention punishment for apologizers is lower than for non-apologizers. Victims expect an apology and punish if they do not receive one. An apology does not help at all after clearly intentionally committed offenses. On the contrary, after such offenses an apology strongly increases punishment compared to remaining silent.
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Talbot Page, Louis Putterman & Bruno Garcia
Journal of Economic Behavior & Organization, November 2013, Pages 34-48
Abstract:
We introduce new treatments of a voluntary contribution mechanism with opportunities to punish in order to see how contributions, punishments and earnings change when punishment is in the form of fines the punisher distributes to other members of her group. The linked punishment-reward set up is of theoretical interest and could represent simultaneous shifts of social disapproval and approval. Conjectures that punishment will be better targeted, and that it will be more substantial for given deviation from others' contributions, receive support. Making punishment redistributive increases contributions and efficiency, even after netting out the design's free resource element.