Commitment and self-control in a prisoner's dilemma game

Humans often make seemingly irrational choices in situations of conflict between a particular smaller-sooner reinforcer and a more abstract, temporally extended, but larger reinforcer. In two experiments, the extent to which the availability of commitment responses-self-imposed restrictions on future choices-might improve self-control in such situations was investigated. Participants played a prisoner's dilemma game against a computer that played a tit-for-tat strategy-cooperating after a participant cooperated, defecting after a participant defected. Defecting produced a small-immediate reinforcer (consisting of points convertible to gift cards) whereas cooperating increased the amount of subsequent reinforcers, yielding a greater overall reinforcer rate. Participants were normally free to cooperate or defect on each trial. Additionally, they could choose to make a commitment response that forced their choice for the ensuing five trials. For some participants, the commitment response forced cooperation; for others, it forced defection. Most participants, with either commitment response available, chose to commit repeatedly despite a minor point loss for doing so. After extended exposure to these contingencies, the commit-to-cooperate group cooperated significantly more than a control group (with no commitment available). The commit-to-defect group cooperated significantly less than the control group. When both commitment alternatives were simultaneously available-one for cooperation and one for defection-cooperation commitment was strongly preferred. In Experiment 2, the commitment alternative was removed at the end of the session; gains in cooperation, relative to the control group, were not sustained in the absence of the self-imposed behavioral scaffold.     

The role of autoshaping in cooperative two-player games between starlings

We report a study of the behavior of starlings in laboratory situations inspired by the “prisoner's dilemma.” Our purpose is to investigate some possible mechanisms for the maintenance of cooperation by reciprocity and to investigate the process of autoshaping at a trial-by-trial level. In Experiment 1, pairs of starlings housed in adjacent cages played a discrete-trial “game” in which food could be obtained only by “cooperation.” In this game, pecking at a response key eliminated the opportunity to obtain food but produced food for the partner. If neither bird pecked, neither had the opportunity to obtain food in that trial. Some level of cooperation persisted for several sessions whether the birds had been pretrained for a high or low probability of pecking at the key. The probability of a cooperative response was higher after trials in which the partner responded (and a reward was obtained) than after trials in which neither bird responded (and no reward was obtained), but the probability of a response was even higher after trials in which the same bird had responded, even though no reward was obtained by the actor in these trials. This behavior did not require visual presence of another player, because similar results were obtained in Experiment 2 (a replicate of Experiment 1 in which the members of the pair could not see each other) and in Experiment 3, a game in which each starling played with a computer responding with “tit for tat.” Using an omission schedule, in which food was given in all trials in which the bird did not peck, Experiment 4 showed that pecking could be maintained by autoshaping. In this experiment, overall probability of pecking decreased with experience, due to a drop in the tendency to peck in consecutive trials. The probability of pecking in trials following a reinforced trial did not decrease with experience. An implementation of the Rescorla–Wagner model for this situation was capable of reproducing molar, but not molecular, aspects of our results. The results violate the predictions of several game-theoretical models for the evolution of cooperation, including tit for tat, generous tit for tat, and the superior win-stay-lose-shift.     

Contingencies of reinforcement in a five-person prisoner's dilemma

As in studies of self-control, a tit-for-tat contingency in an iterated prisoner's dilemma game creates a conflict between maximization of local and global reinforcement. The present experiments examine this conflict in a multiplayer prisoner's dilemma game. Versus tit for tat, cooperation corresponds to self-control; defection, always immediately reinforced, corresponds to impulsiveness. Three experiments examined sensitivity of behavior to the global reinforcement contingency imposed by tit for tat. Undergraduates played a five-player prisoner's dilemma game against four dummy players programmed to play tit for tat or randomly. With tit for tat, a player's cooperation (or defection) increased dummy players' cooperation (or defection) on subsequent trials-reinforcing cooperation and punishing defection in the long run. Participants cooperated at a higher rate when the dummy players played tit for tat than when the dummy players played randomly. These results are consistent with findings in corresponding studies of self-control. Some participants, caught in a trap of mutual defection with the tit-for-tat playing dummy players, came to cooperate when the tit-for-tat contingency was reset ("forgiving" participants' previous defections) during a pause in the game. This increase was a result of the combined effects of a pause and reset; neither pausing nor resetting independently resulted in an increase in cooperation.     

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.     

A Description–Experience Gap in Social Interactions: Information about Interdependence and Its Effects on Cooperation

In social interactions, decision makers are often unaware of their interdependence with others, precluding the realization of shared long‐term benefits. In an experiment, pairs of participants played an Iterated Prisoner's Dilemma under various conditions involving differing levels of interdependence information. Each pair was assigned to one of four conditions: “No‐Info” players saw their own actions and outcomes, but were not told that they interacted with another person; “Min‐Info” players knew they interacted with another person but still without seeing the other's actions or outcomes; “Mid‐Info” players discovered the other's actions and outcomes as they were revealed over time; and “Max‐Info” players were also shown a complete payoff matrix mapping actions to outcomes from the outset and throughout the game. With higher levels of interdependence information, we found increased individual cooperation and mutual cooperation, driven by increased reciprocating cooperation (in response to a counterpart's cooperation). Furthermore, joint performance and satisfaction were higher for pairs with more information. We discuss how awareness of interdependence may encourage cooperative behavior in real‐world interactions. Copyright © 2013 John Wiley & Sons, Ltd.     

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.     

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.     

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.     

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.     

Risk and Prisoner's Dilemma: A Reinterpretation of Coombs' Re‐parameterization

We propose a model to measure risk in a prisoner's dilemma based on Coombs' (1973) re‐parameterization of the game as an individual risk decision‐making task that chooses between a gamble of cooperation and another gamble of defection. Specifically, we propose an index, r, to represent the risk associated with cooperation relative to defection. In conjunction with Rapoport's (1967) index of cooperation (K), our formulation of risk allows us to construct games that vary in risk (as indexed by r) while controlling for cooperativeness (as indexed by K). Following utility analysis that models risk seeking as a convex utility function and risk averse as a concave function, we predict that risk‐seeking people cooperate more in games that the cooperation choice is more risky, whereas risk‐averse people cooperate more in games that the cooperation choice is less risky. In the three studies that we varied game parameters, used different measures of risk orientation and prosocial orientation and used different experimental procedures, we found robust results supporting our predictions. Theoretical analysis of our formulation further suggests that risk and cooperativeness of a prisoner's dilemma game is not entirely independent. Games that have a higher cooperativeness index are necessarily more risky. Copyright © 2011 John Wiley & Sons, Ltd.     

金钱惩罚促进Stroop任务中的行为表现

本研究通过Stroop任务和修改版MIDT相结合,目的是考察不同额度金钱惩罚对Stroop任务行为表现的影响。结果发现：（1）无论是中性试次,一致试次还是不一致试次,金钱惩罚不仅减少了被试的行为反应时,而且提高了正确率;（2）非惩罚条件与惩罚条件下的冲突效应以及其他不同额度惩罚条件下的冲突效应差异不显著;（3）金钱惩罚对不一致试次反应时的影响与个体的惩罚敏感性呈显著负相关,而与奖赏敏感性无关。结果表明,金钱惩罚能够促进个体的一般行为表现,但是不会提高冲突抑制能力。同时,金钱惩罚对认知行为的影响与其惩罚敏感性密切相关。     

金钱惩罚促进Stroop任务中的行为表现

本研究通过Stroop任务和修改版MIDT相结合,目的是考察不同额度金钱惩罚对Stroop任务行为表现的影响。结果发现：（1）无论是中性试次,一致试次还是不一致试次,金钱惩罚不仅减少了被试的行为反应时,而且提高了正确率;（2）非惩罚条件与惩罚条件下的冲突效应以及其他不同额度惩罚条件下的冲突效应差异不显著;（3）金钱惩罚对不一致试次反应时的影响与个体的惩罚敏感性呈显著负相关,而与奖赏敏感性无关。结果表明,金钱惩罚能够促进个体的一般行为表现,但是不会提高冲突抑制能力。同时,金钱惩罚对认知行为的影响与其惩罚敏感性密切相关。     

The Advantage of Democratic Peer Punishment in Sustaining Cooperation within Groups

In social dilemma situations, individuals benefit from uncooperative behavior while exploiting resources of the collective. One prominent solution to prevent uncooperative behavior and to increase cooperation is to establish a system of costly peer punishment, that is, the possibility for every individual involved in the dilemma to impose costly punishment on interaction partners. However, recent research revealed that, in contrast to a situation without punishment, peer punishment is inefficient and maladaptive in the sense that the total payoff is reduced and punishment of cooperative individuals (i.e., antisocial punishment) is possible. In the present work, we propose that a system of democratic peer punishment, that is, direct and equal participation of each individual in the punishment decision‐making process with punishment only executed when a majority has voted for its execution, can address the shortcomings of a peer punishment system. Using iterated public goods games, we show higher cooperation levels, higher total payoffs, and reduced executed punishment in the democratic compared with a peer punishment system. Moreover, we document that fairness perceptions, satisfaction, and interpersonal trust are increased in the democratic punishment system. Implications for how cooperation and democratic punishment systems may evolve are discussed. Copyright © 2018 John Wiley & Sons, Ltd.     

高功能孤独症儿童的合作行为

合作行为是一种重要的亲社会行为, 对儿童的社会适应具有重要意义, 而孤独症儿童的典型特征是社会功能存在缺陷, 从而导致合作行为的缺乏。以往研究未能就孤独症儿童在不同合作任务类型中的表现做出区分, 本研究采用经典的囚徒困境博弈和合作性工具任务比较了6~12岁的高功能孤独症儿童和正常发展儿童在不同任务中的合作行为。结果显示高功能孤独症儿童和正常儿童在囚徒困境中的合作行为没有显著差异, 然而, 他们在工具性任务中表现出比正常儿童更低水平的合作行为。这说明高功能孤独症儿童在对认知能力有不同要求的合作任务中的表现不同。     

道德与关系惩罚对初中生公共物品困境中合作行为的影响

本研究模拟公共物品两难困境范式,以初中生为被试,通过两个实验分别考察道德惩罚和关系惩罚对不同性别和社会价值取向个体合作行为的影响。结果发现:(1)两种惩罚条件下初中生的合作水平均显著高于无惩罚条件,但当惩罚撤除后只有关系惩罚条件下的效应还存在;(2)初中女生在两种惩罚条件下的合作水平均显著高于无惩罚条件,而男生只在关系惩罚条件下出现该情况;(3)亲社会取向与亲自我取向初中生在两种惩罚阶段均表现出更高的合作水平,但在惩罚撤除后,只有亲社会取向者保持了高合作水平。这些结果表明,关系惩罚的作用较为持久,且对男生的影响更为突出,不过两种惩罚在亲社会取向者身上均显现出延后效应。     

Effects of reward magnitude frames on measures of delay discounting in a hypothetical money scenario

The current study analyzed the effects of three frames of reward magnitude—quantity, volume, and duration—on the rate at which college students discounted hypothetical, delayed monetary rewards. Hypothetical scenarios were presented using the fill-in-the-blank discounting questionnaire and participants made choices between immediate and delayed hypothetical monetary rewards. Scenarios framed the monetary choices as (a) quantity of dollar bills, (b) height (inches) of a stack of dollar bills, and (c) duration of time spent in a hypothetical cash machine to collect dollar bills. For each scenario, participants' subjective values were used to calculate the area under the curve (AuC). Framing resulted in a moderate effect size: The duration frame yielded significantly smaller AuC values compared to the quantity and volume frames. Thus, the framing of reward magnitude was a significant variable in controlling discounting rates for hypothetical, delayed monetary rewards. Subsequent investigations should be aware of the independent effects of the reward magnitude frames on delay discounting rates.     

公共物品困境中的突显身份效应及合作动机对合作行为影响

从合作动机的激发与破坏的角度探讨公共物品困境中突显身份对合作行为的影响,同时考察社会价值取向与突显身份之间的关系。结果表明：突显合作者与突显不合作者两种方式都会提高被试的合作水平;两种突显方式的作用机制不同。突显合作者条件下,被试的合作行为受内在动机和外在动机的共同影响。而突显不合作者则会破坏被试合作的内在动机,外在动机对提高合作行为起主要作用;突显合作者条件下,合作取向的被试更多受内在动机的影响,而非合作取向的被试则更多受外在动机的影响。在突显不合作者的条件下,合作取向和非合作取向被试的合作行为都受外在动机的影响较大。     

The effect of decision timing on the willingness to costly reward cooperation and punish noncooperation: Sanctioning the past,the present,or the future

Numerous studies have demonstrated that sanctions can promote cooperation. However, it is important to know not only that sanctions can work but also under what conditions people are actually willing to sanction cooperation positively (i.e., reward) or noncooperation negatively (i.e., punish). In this article, we demonstrate that people use sanctions less often and sanction more mildly when they decide about sanctioning before (instead of after) the occurrence of others' (non)cooperation (Experiments 1 and 2), regardless of whether they decide directly afterwards or after a time delay (Experiment 2). Moreover, we reveal that beforehand (as compared with afterwards) people have not yet formed clear sanctioning preferences (Experiment 3). These findings corroborate our reasoning that the decision environment beforehand induces nonconsequential reasoning and thereby hampers people's willingness to sanction. We discuss the theoretical, methodological, and practical implications of our work.     

HOW SHOULD WE BEHAVE? A REVIEW OF REASONS AND PERSONS BY DEREK PARFIT

In this book Parfit attempts to develop a rational, non-religious ethics. Instead of asking, “What does God tell us to do?” he asks, “What does reason tell us to do?” Given a set of simple assumptions, he considers whether it is possible to be consistently selfish or consistently good. Analyses of personal dilemmas (problems of self-control) and moral dilemmas (problems of social cooperation) show that neither consistent selfishness nor consistent goodness is logically possible. Instead, a fine balance must be maintained between, on the one hand, our immediate versus long-term good and, on the other, our own good versus that of other people. Ultimately Parfit fails to develop a formula by which such a balance may be struck. Parfit''s analysis is consistent with behavioral analysis in its reductionistic view of the self and the parallel it draws between relations with other people and relations with oneself at other times. Parfit''s analysis is inconsistent with behaviorism in its view of the mind as internal, available to introspection, and able to cause behavior. His nonfunctional mentalism leads Parfit to inconsistencies and blocks the path to a consistent ethics. Teleological behaviorism''s view of the mind in terms of patterns of overt behavior is not hampered by these inconsistencies and may lead to a functional rather than purely rational ethics.