Expectation and cooperation in prisoner’s dilemmas: The moderating role of game riskiness

This paper investigated the effect of risk orientation, game riskiness, and expectation of cooperation on cooperation in one-shot prisoner’s dilemmas (PD). Participants in pairs played PD games that varied on game riskiness such that for half of the games cooperation was more risky than defection (more risky games) while for another half cooperation was less risky (less risky games). They estimated how likely it was that the other player was going to cooperate (expectation of cooperation) before they made their cooperation/defection decision on each game. Supporting the Goal/Expectation Hypothesis, we replicated the effect that expectation of cooperation enhanced cooperation. We also found that risk-seeking individuals cooperated more in more risky games whereas risk-averse individuals cooperated more in less risky games. More importantly, we found that game riskiness moderated the effect of expectation of cooperation on cooperation. The positive effect of expectation of cooperation on cooperation was stronger for more risky games than for less risky games. Our results illustrated how the relation between expectation and cooperation as stipulated by the Goal/Expectation Hypothesis was moderated by riskiness of the situations.     

Defection in the dark? A randomized‐response investigation of cooperativeness in social dilemma games

As previous research has demonstrated numerous times, humans show a robust tendency for cooperation. However, part—or indeed all—of this cooperativeness may be due to socially desirable responding. To address this problem, we propose and apply a new approach for the unbiased measurement of cooperativeness in social dilemma games. Specifically, we employ an extension of the randomized‐response technique (RRT). The RRT protects the privacy of respondents by adding random noise to their responses. It thus encourages more honest responding and thereby provides less biased estimates of sensitive attributes. In a large‐scale study with 2043 respondents we maximized anonymity in a one‐shot prisoner's dilemma game through use of the RRT. Comparing the prevalence rates for cooperation obtained via the RRT with those from direct self‐report showed that traditional direct questioning formats overestimate cooperation rates, with a relative bias of 18%. This finding suggests that to a considerable extent, self‐reported cooperation is due to socially desirable responding, rather than actual cooperativeness. However, our results also demonstrate that cooperation remains substantial even under conditions of maximized anonymity. Copyright © 2011 John Wiley & Sons, Ltd.     

Prior experience and patterning in a prisoner's dilemma game

Female college students first played a pseudo-prisoner's dilemma (PPD) game with the experimenter, who followed a fixed strategy. In the first experiment the experimenter's strategies for different groups of subjects were: (a) play tit-for-tat; (b) play randomly; (c) always cooperate; (d) always defect (‘cooperation’ and ‘defection’, defined as in an actual prisoner's dilemma game). Only the tit-for-tat group increased cooperation over trials; other groups decreased cooperation. After playing the PPD with the experimenter, subjects played an actual prisoner's dilemma (PD) game with each other. In the PD game, subjects began cooperating moderately but cooperation deteriorated regardless of what the experimenter's strategy had been in the earlier (PPD) game. In a second experiment, subjects again played a PPD game with the experimenter and then played a PD game with each other. Half played one trial at a time as in the first experiment while half played in patterns of four trials at a time. In the PD game, patterning of trials retarded the development of mutual defection regardless of previous experience. The cooperation-preserving effect of patterning of trials in this social task is compared with similar effects on individual tasks involving self-control and risk-aversion. © 1998 John Wiley & Sons, Ltd.     

Lead Us (Not) into Temptation: Testing the Motivational Mechanisms Linking Honesty–Humility to Cooperation

Over the past decades, there has been considerable interest in individual differences in cooperative behaviour and how these can be explained. Whereas the Honesty–Humility dimension from the HEXACO model of personality has been identified as a consistent predictor of cooperation, the underlying motivational mechanisms of this association have remained unclear—especially given the confound between the temptation to exploit others and the fear of being exploited as motivational drivers of defection in social dilemmas. In a reanalysis and a new experiment, we tease apart these mechanisms by manipulating the rank order of pay‐offs in a symmetric two‐person game paradigm, essentially implementing the classic prisoner's dilemma, stag hunt, and chicken games. Results revealed that Honesty–Humility predicted cooperation specifically in the games in which temptation was a potential motivator of defection, whereas it did not account for cooperation in those games in which only fear implied defection. Our findings thereby shed light on the underlying motivational mechanisms of the Honesty–Humility–cooperation link and, more generally, demonstrate how economic games can be used to disentangle such mechanisms. Copyright © 2018 European Association of Personality Psychology     

Probability of reciprocation in repeated prisoner's dilemma games

Both social cooperation and self‐control require reciprocation. In social cooperation situations a single person's cooperative act, if not reciprocated by others, would be unreinforced both immediately and in the long term. Similarly, a single act of self‐control (refusing a single cigarette, for example), if not followed up by other such acts, would also be unreinforced immediately and in the long term. The present experiments varied probability of reciprocation in a prisoner's dilemma‐like game that could resemble a social cooperation or a self‐control situation. Participants earned points by playing against a computer. The computer offered the participant a choice between 5 or 6 points (‘cooperation’ by the computer) or between 1 or 2 points (‘defection’ by the computer). The participant's choice of the lesser alternative (‘cooperation’) or the greater alternative (‘defection’) on the current trial led, respectively, to cooperation or defection by the computer on the next trial with a probability (probability of reciprocation, PR) which could vary. When PR was greater than 63%, consistent cooperation maximized the participant's earnings. When PR was less than 63%, defection maximized earnings. Three conditions were studied: PR signaled by spinners; PR unsignaled; PR unsignaled with participants believing that they were playing with another person, not the computer. With PR = 100% (‘tit‐for‐tat’) and PR = 50%, the modal participant maximized earnings under all three conditions. With PR = 75%, participants maximized earnings only when PR was signaled. These results indicate that differences between people's tendency to cooperate with other people (social cooperation) and their tendency to cooperate with their own future interests (self‐control) may lie in differences in subjective PR. Copyright © 2001 John Wiley & Sons, Ltd.     

Effects of initial choices in the prisoner's dilemma

In the two‐person prisoner's dilemma game (PDG), there is considerable evidence that the tit‐for‐tat (TFT) strategy is most effective in inducing the other person to cooperate. One of the important features of the TFT strategy is that it cooperates on the first trial. We varied the initial choices of a simulated other, and tested the effects of (a) initial choices (cooperation or defection), and (b) persistence of initial choices: unilateral cooperation (or defection) on the first trial, first two trials, or first four trials. Results showed that a cooperative strategy—one that starts with cooperative choices—induced greater cooperation than a strategy that started with defections. The results of this study clearly show that (a) a cooperative strategy—one that initiates unilateral cooperation at the outset and then adopts a TFT strategy—is very effective in inducing subsequent cooperation from the other party, (b) the effectiveness of a cooperative strategy varies directly with the cooperative orientation of the other party (a cooperative strategy is more effective against a cooperative than a competitive person), and (c) initial cooperation is more effective if it is repeated more than once. Copyright © 2002 John Wiley & Sons, Ltd.     

HOBBES AND GAME THEORY REVISITED: ZERO‐SUM GAMES IN THE STATE OF NATURE

The aim of this paper is to critically review the game‐theoretic discussion of Hobbes and to develop a game‐theoretic interpretation that gives due attention both to Hobbes's distinction between “moderates” and “dominators” and to what actually initiates conflict in the state of nature, namely, the competition for vital goods. As can be shown, Hobbes's state of nature contains differently structured situations of choice, the game‐theoretic representation of which requires the prisoner's dilemma and the assurance game and the so‐called assurance dilemma. However, the “state of war” ultimately emerges from situations that cannot be described by any of these games because they represent zero‐sum games in which the outcome of mutual cooperation does not exist.     

Decision making in the prisoner's dilemma game: The effect of exit on cooperation and social welfare

The prisoner's dilemma game is a mixed‐motive game that offers two players the simultaneous choice between a cooperative and a defective alternative. An often neglected aspect of such a binary‐choice game, however, is that in many real‐life encounters, people can choose not only to cooperate or defect, but they also have a third option: to exit the social dilemma. Although in the literature a consensus has emerged that the addition of an exit opportunity benefits cooperation, there is only scant research into its effect on social welfare. In order to allow a direct comparison of cooperation rates and welfare levels across binary‐choice and trinary‐choice games, in this study, we used a design in which the same participants played similar games with and without an exit option (i.e., a within‐subjects design), and this in a range of structural variations. The findings of our study indicated that the aggregated outcome of both players is generally lower in games with an exit option than in games without an exit option. Moreover, our results showed that the efficiency of the exit option strongly depends on the specific outcome structure of the game (in terms of its endowment size, (a)symmetry, and level of noncorrespondence). In the discussion, it is argued that the implementation of an exit option as a strategy to increase social welfare should be critically assessed.     

Reason and Pareto‐Optimization

This paper takes up David Gauthier's most recent (2013) defense of the rationality of cooperation in prisoner's dilemmas. In that defense, Gauthier argues for a Pareto‐optimizing theory of rational choice. According to Gauthier, rational action should sometimes aim at Pareto‐optimization, and cooperation in prisoner's dilemmas is rational because it is Pareto‐optimizing. I argue that Pareto‐optimization cannot justify cooperation in the prisoner's dilemma in a manner that is also consistent with Gauthier's other desiderata. Either: (1) the rationality of cooperation must derive from what is beneficial for the group rather than what is beneficial for the individual, leaving the individual qua individual without any reason to cooperate, or (2) Gauthier cannot explain why defecting in prisoner's dilemmas is not also rational.     

Empathy‐induced altruism in a prisoner's dilemma II: what if the target of empathy has defected?

What if participants in a one‐trial prisoner's dilemma know before making their decision that the other person has already defected? From the perspective of classic game theory, a dilemma no longer exists. It is clearly in their best interest to defect too. The empathy‐altruism hypothesis predicts, however, that if they feel empathy for the other, then a dilemma remains: self‐interest counsels defection; empathy‐induced altruism counsels not. This motivational conflict should lead at least some empathically aroused individuals not to defect. To test this prediction, we placed 60 undergraduate women in a one‐trial prisoner's dilemma in which they knew the other had already defected. Among those not induced to feel empathy, very few (0.05) did not defect in return. Among those induced to feel empathy for the other, almost half (0.45) did not defect. These results underscore the power of empathy‐induced altruism to affect responses in a prisoner's dilemma. Copyright © 2001 John Wiley & Sons, Ltd.     

Framing prisoners and chickens: Valence effects in the prisoner’s dilemma and the chicken game

In an experimental study, we investigated how decisions in social dilemmas are affected by the valence of outcomes that are at stake. Prospect theory states that individuals are risk-averse when outcomes are framed as gains, and risk-seeking when outcomes are framed as losses. On the basis of this framework, previous research on social dilemmas has addressed the question of whether people are more cooperative in the negative domain than in the positive domain, but this research has led to inconsistent results. A possible explanation for this is that in many social dilemmas it is unclear whether cooperation or defection is the risky choice. In the current paper, we compare the well-studied prisoner’s dilemma with the less studied chicken game. Whereas in the prisoner’s dilemma it is unclear what constitutes the risky option, in the chicken game the risky option is quite clear. Consistent with predictions, we found in the chicken game more defection in the loss frame than in the gain frame, but no difference between the gain and loss frame in the prisoner’s dilemma. Moreover, choices were predicted by risk attitude in the chicken game, but not in the prisoner’s dilemma.     

No Place to Hide: When Shame Causes Proselfs to Cooperate

Shame is considered a social emotion with action tendencies that elicit socially beneficial behavior. Yet, unlike other social emotions, prior experimental studies do not indicate that incidental shame boosts prosocial behavior. Based on the affect as information theory, we hypothesize that incidental feelings of shame can increase cooperation, but only for self-interested individuals, and only in a context where shame is relevant with regards to its action tendency. To test this hypothesis, cooperation levels are compared between a simultaneous prisoner's dilemma (where “defect” may result from multiple motives) and a sequential prisoner's dilemma (where “second player defect” is the result of intentional greediness). As hypothesized, shame positively affected proselfs in a sequential prisoner's dilemma. Hence ashamed proselfs become inclined to cooperate when they believe they have no way to hide their greediness, and not necessarily because they want to make up for earlier wrong-doing.     

Effects of Gender on Costly Punishment

Women are often believed to be more cooperative and less egoistic than men. In the present study, we examined whether people punish women for failing to live up to these benevolent gender stereotypes. Participants played a prisoner's dilemma game with female and male partners who either cooperated or defected. Participants were offered a costly punishment option. They could spend money to decrease the payment of their partners. In Experiment 1, participants spent more money to punish the defection of female in comparison to male partners, but this effect of partner gender on punishment was indirect rather than direct: Participants were more likely to cooperate with female partners than with male partners, which gave them more opportunity for moralistic punishment. In Experiments 2 and 3, we examined the effects of the participants' own gender on cooperation and punishment of female and male partners. Female participants cooperated more with female partners than with male partners while male participants treated female and male partners equally. We conclude that the effect of facial gender on punishment are indirect rather than direct. The results also showed that women, in contrast to men, tended to make decisions that can be considered more social and less rational from an economic point of view, consistent with social‐role theory and evolutionary accounts. Copyright © 2017 John Wiley & Sons, Ltd.     

The evil eye: Eye gaze and competitiveness in social decision making

We demonstrate that a person's eye gaze and his/her competitiveness are closely intertwined in social decision making. In an exploratory examination of this relationship, Study 1 uses field data from a high‐stakes TV game show to demonstrate that the frequency by which contestants gaze at their opponent's eyes predicts their defection in a variant on the prisoner's dilemma. Studies 2 and 3 use experiments to examine the underlying causality and demonstrate that the relationship between gazing and competitive behavior is bi‐directional. In Study 2, fixation on the eyes, compared to the face, increases competitive behavior toward the target in an ultimatum game. In Study 3, we manipulate the framing of a negotiation (cooperative vs. competitive) and use an eye tracker to measure fixation number and time spent fixating on the counterpart's eyes. We find that a competitive negotiation elicits more gazing, which in turn leads to more competitive behavior.     

Empathy‐induced altruism in a prisoner's dilemma

Can empathy‐induced altruism motivate a person to cooperate in a prisoner's dilemma? To answer this question, 60 undergraduate women were placed in a one‐trial prisoner's dilemma, and empathy for the other person was manipulated. Regardless of whether the dilemma was framed as a social exchange or as a business transaction, cooperation was significantly higher among those women led to feel empathy for the other than among those not led to feel empathy. Among those not led to feel empathy, the business frame reduced cooperation, lending support to the idea of an exemption on moral motivation in business transactions. Lack of a business exemption on empathy‐induced altruism supported the suggestion that altruism is not simply a type of moral motivation, but is a distinct form of prosocial motivation. Copyright © 1999 John Wiley & Sons, Ltd.     

Does parochial cooperation exist in childhood and adolescence? A meta-analysis

Although previous meta-analytic evidence supports the existence of parochialism in cooperation among adults, the extent to which children and adolescents are more willing to incur a personal cost to benefit ingroups, compared to outgroups, is not yet clear. We provide the first meta-analysis on the existence and magnitude of parochialism in cooperation among pre-adults. Based on 20 experimental economics studies (k = 69, N = 5268, age = 3–19, 12 countries, published 2008–2019), a multilevel meta-analytic model revealed a small overall effect size indicating that children and adolescents were more cooperative towards ingroups (d = 0.22, 95% CI [0.07, 0.38]). A series of single-moderator analyses tested for the following conditions: participant age and sex; game type ([mini-]dictator game, prisoner's dilemma, public goods dilemma, trust game, ultimatum game); outcome interdependence; membership manipulation (between- vs. within-subjects); group type (natural vs. experimental); reward type (monetary vs. non-monetary); and country of the participant. Parochial cooperation did not vary with participants' age. Parochialism was larger in non-interdependent (dictator-type) compared to interdependent (bargaining and social dilemma) games. There were no moderating effects of group type, membership manipulation or reward type. To provide more data on how parochialism develops, primary studies should report age ranges more precisely and use more restricted age groups.     

The effects of feelings of guilt on the behaviour of uncooperative individuals in repeated social bargaining games: An affect-as-information interpretation of the role of emotion in social interaction

In two studies we found that feelings of guilt provoke individuals to cooperate in repeated social bargaining games (a prisoner's dilemma in Study 1 and an ultimatum game in Study 2). Feelings of guilt were either experimentally manipulated (Study 1) or assessed via self-report (Study 2) after participants had played one round of a social bargaining game. As predicted, individuals who experienced feelings of guilt (compared to individuals who felt no guilt) after pursuing a non-cooperative strategy in the first round of play, displayed higher levels of cooperation in the subsequent round of play (even one week later). Results are discussed in terms of an “affect-as-information” model, which suggests that non-cooperating individuals who experience the negative affective state associated with guilt in a social bargaining game may be using this feeling state as “information” about the future costs of pursuing an uncooperative strategy. Because in guilt the focus is on the specific, individuals are capable of ridding themselves of this emotional state through action (Lewis, 1993, p. 570)     

Larger reward values alone are not enough to entice more cooperation

Two experiments using an iterated prisoner's dilemma game examined under which conditions participants' cooperation rates would either change due to monetary value changes (e.g., 3 cents to 3 dollars) or not change due to numeric value changes (e.g., 3 dollars to 300 cents). A total of 102 university students played the game against a computer that employed one of four strategies across blocks. Results showed high rates of cooperation when participants played against a tit-for-tat strategy and low rates of cooperation against a random strategy. There was no change in cooperation rates due to changes in numeric value alone and a decrease in cooperation rates when large monetary values were at stake. Cooperation rates were higher and cooperation responses slower at earlier stages of the game. I argue that people's ability to strategize plays a key role in the changing rates and speed of cooperative behaviour in the prisoner's dilemma.     

The effect of westernization on cooperative behaviour in Central Africa

The traditional ethos of Central African societies emphasises cooperation and sharing. In a Prisoner's Dilemma game, traditional Tonga men and women in Zambia played more cooperatively than westernized Tonga people and Asian students. Their greater cooperativeness showed most clearly in their tendency to make a cooperative response even after their partner had defected, whereas other groups tended to meet defection with defection.     

Dynamic probability of reinforcement for cooperation: Random game termination in the centipede game

Experimental games have previously been used to study principles of human interaction. Many such games are characterized by iterated or repeated designs that model dynamic relationships, including reciprocal cooperation. To enable the study of infinite game repetitions and to avoid endgame effects of lower cooperation toward the final game round, investigators have introduced random termination rules. This study extends previous research that has focused narrowly on repeated Prisoner's Dilemma games by conducting a controlled experiment of two‐player, random termination Centipede games involving probabilistic reinforcement and characterized by the longest decision sequences reported in the empirical literature to date (24 decision nodes). Specifically, we assessed mean exit points and cooperation rates, and compared the effects of four different termination rules: no random game termination, random game termination with constant termination probability, random game termination with increasing termination probability, and random game termination with decreasing termination probability. We found that although mean exit points were lower for games with shorter expected game lengths, the subjects' cooperativeness was significantly reduced only in the most extreme condition with decreasing computer termination probability and an expected game length of two decision nodes.