Moral labels increase cooperation and costly punishment in a Prisoner's Dilemma game with punishment option

Time pressure and deliberation affect moral punishment

The deliberate-morality account implies that moral punishment should be decreased with time pressure and increased with deliberation while the intuitive-morality account predicts the opposite. In three experiments, moral punishment was examined in a simultaneous one-shot Prisoner's Dilemma game with a costly punishment option. The players cooperated or defected and then decided whether or not to punish their partners. In Experiment 1, the punishment decisions were made without or with time pressure. In Experiment 2, the punishment decisions were immediate or delayed by pauses in which participants deliberated their decisions. In Experiment 3, participants were asked to deliberate self-interest or fairness before deciding whether to punish their partners. Different types of punishment were distinguished using the cooperation-and-punishment model. In Experiment 1, time pressure decreased moral punishment. In Experiment 2, deliberation increased moral punishment. So far, the evidence supports the deliberate-morality account. Experiment 3 demonstrates that the effect of deliberation depends on what is deliberated. When participants deliberated self-interest rather than fairness, moral punishment was decreased. The results suggest that unguided deliberation increases moral punishment, but the effects of deliberation are modulated by the type of deliberation that takes place. These results strengthen a process-based account of punishment which offers a more nuanced understanding of the context-specific effect of deliberation on moral punishment than the deliberate-morality account.

Language-based game theory in the age of artificial intelligence

Understanding human behaviour in decision problems and strategic interactions has wide-ranging applications in economics, psychology and artificial intelligence. Game theory offers a robust foundation for this understanding, based on the idea that individuals aim to maximize a utility function. However, the exact factors influencing strategy choices remain elusive. While traditional models try to explain human behaviour as a function of the outcomes of available actions, recent experimental research reveals that linguistic content significantly impacts decision-making, thus prompting a paradigm shift from outcome-based to language-based utility functions. This shift is more urgent than ever, given the advancement of generative AI, which has the potential to support humans in making critical decisions through language-based interactions. We propose sentiment analysis as a fundamental tool for this shift and take an initial step by analysing 61 experimental instructions from the dictator game, an economic game capturing the balance between self-interest and the interest of others, which is at the core of many social interactions. Our meta-analysis shows that sentiment analysis can explain human behaviour beyond economic outcomes. We discuss future research directions. We hope this work sets the stage for a novel game-theoretical approach that emphasizes the importance of language in human decisions.

People punish defection, not failures to conform to the majority

Do people punish others for defecting or for failing to conform to the majority? In two experiments, we manipulated whether the participants' partners cooperated or defected in the majority of the trials of a Prisoner's Dilemma game. The effects of this base-rate manipulation on cooperation and punishment were assessed using a multinomial processing tree model. High compared to low cooperation rates of the partners increased participants' cooperation. When participants' cooperation was not enforced through partner punishment, the participants' cooperation was closely aligned to the cooperation rates of the partners. Moral punishment of defection increased when cooperation rates were high compared to when defection rates were high. However, antisocial punishment of cooperation when defection rates were high was much less likely than moral punishment of defection when cooperation rates were high. In addition, antisocial punishment was increased when cooperation rates were high compared to when defection rates were high. The latter two results contradict the assumption that people punish conformity-violating behavior regardless of whether the behavior supports or disrupts cooperation. Punishment is thus sensitive to the rates of cooperation and defection but, overall, the results are inconsistent with the idea that punishment primarily, let alone exclusively, serves to enforce conformity with the majority.

Communicating emotions, but not expressing them privately, reduces moral punishment in a Prisoner's Dilemma game

The existence of moral punishment, that is, the fact that cooperative people sacrifice resources to punish defecting partners requires an explanation. Potential explanations are that people punish defecting partners to privately express or to communicate their negative emotions in response to the experienced unfairness. If so, then providing participants with alternative ways to privately express or to communicate their emotions should reduce moral punishment. In two experiments, participants interacted with cooperating and defecting partners in a Prisoner's Dilemma game. After each round, participants communicated their emotions to their partners (Experiments 1 and 2) or only expressed them privately (Experiment 2). Each trial concluded with a costly punishment option. Compared to a no-expression control group, moral punishment was reduced when emotions were communicated to the defecting partner but not when emotions were privately expressed. Moral punishment may thus serve to communicate emotions to defecting partners. However, moral punishment was only reduced but far from being eliminated, suggesting that the communication of emotions does not come close to replacing moral punishment. Furthermore, prompting participants to focus on their emotions had undesirable side-effects: Privately expressing emotions diminished cooperation, enhanced hypocritical punishment (i.e., punishment of defecting partners by defecting participants), and induced an unspecific bias to punish the partners irrespective of their actions.

Moral reasoning and moral competence as predictors of cooperative behavior in a social dilemma

The level of moral development may be crucial to understand behavior when people have to choose between prioritizing individual gains or pursuing general social benefits. This study evaluated whether two different psychological constructs, moral reasoning and moral competence, are associated with cooperative behavior in the context of the prisoner's dilemma game, a two-person social dilemma where individuals choose between cooperation or defection. One hundred and eighty-nine Mexican university students completed the Defining Issues Test (DIT-2; measuring moral reasoning) and the Moral Competence Test (MCT) and played an online version of the prisoner's dilemma game, once against each participant in a group of 6-10 players. Our results indicate that cooperative behavior is strongly affected by the outcomes in previous rounds: Except when both participants cooperated, the probability of cooperation with other participants in subsequent rounds decreased. Both the DIT-2 and MCT independently moderated this effect of previous experiences, particularly in the case of sucker-outcomes. Individuals with high scores on both tests were not affected when in previous rounds the other player defected while they cooperated. Our findings suggest that more sophisticated moral reasoning and moral competence promote the maintenance of cooperative behaviors despite facing adverse situations.

A validation of the two-high threshold eyewitness identification model by reanalyzing published data

The two-high threshold (2-HT) eyewitness identification model serves as a new measurement tool to measure the latent cognitive processes underlying eyewitness identification performance. By simultaneously taking into account correct culprit identifications, false innocent-suspect identifications, false filler identifications in culprit-present and culprit-absent lineups as well as correct and false lineup rejections, the model capitalizes on the full range of data categories that are observed when measuring eyewitness identification performance. Thereby, the model is able to shed light on detection-based and non-detection-based processes underlying eyewitness identification performance. Specifically, the model incorporates parameters for the detection of culprit presence and absence, biased selection of the suspect and guessing-based selection among the lineup members. Here, we provide evidence of the validity of each of the four model parameters by applying the model to eight published data sets. The data sets come from studies with experimental manipulations that target one of the underlying processes specified by the model. Manipulations of encoding difficulty, lineup fairness and pre-lineup instructions were sensitively reflected in the parameters reflecting culprit-presence detection, biased selection and guessing-based selection, respectively. Manipulations designed to facilitate the rejection of culprit-absent lineups affected the parameter for culprit-absence detection. The reanalyses of published results thus suggest that the parameters sensitively reflect the manipulations of the processes they were designed to measure, providing support of the validity of the 2-HT eyewitness identification model.

Playing with words: Do people exploit loaded language to affect others’ decisions for their own benefit?

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

Cognitive load decreases cooperation and moral punishment in a Prisoner's Dilemma game with punishment option

The present study serves to test whether cooperation and moral punishment are affected by cognitive load. Dual-process theories postulate that moral behavior is intuitive which leads to the prediction that cooperation and moral punishment should remain unaffected or may even increase when cognitive load is induced by a secondary task. However, it has also been proposed that cognitive control and deliberation are necessary to choose an economically costly but morally justified option. A third perspective implies that the effects of cognitive load may depend on the specific processes involved in social dilemmas. In the present study, participants played a simultaneous Prisoner’s Dilemma game with a punishment option. First, both players decided to cooperate or defect. Then they had the opportunity to punish the partners. In the cognitive-load group, cognitive load was induced by a continuous tone classification task while the no-load group had no distractor task. Under cognitive load, cooperation and moral punishment decreased in comparison to the no-load condition. By contrast, hypocritical and antisocial punishment were not influenced by the dual-task manipulation. Increased cognitive load was associated with a bias to punish the partners irrespective of the outcome of the Prisoner’s Dilemma game, suggesting that punishment was applied less purposefully in the cognitive-load condition. The present findings are thus in line with the idea that the availability of cognitive resources does not always have a suppressive effect on moral behaviors, but can have facilitating effects on cooperation and moral punishment.