This article introduces a new violation of a law of probability, likelihood neglect bias. The bias occurs when one is (i) aware that some evidence is more likely given one hypothesis rather than another but (ii) that evidence does not cause them to raise their probability for the former hypothesis relative to the latter. The Monty Hall problem illustrates this bias, although the bias is potentially present in other contexts as well. Unlike previous studies, the present study shows that incorrect responses to the problem are attributable to failure to realize the implications of likelihoods (i.e., likelihood neglect) instead of unawareness of what the likelihoods are. Likelihood neglect is also distinguished from other biases which it is occasionally confused with, and a theoretical explanation of likelihood neglect is proposed. Experimental results further indicate that a new approach—the mental simulations approach—showed a large effect in reducing likelihood neglect and increasing correct probabilities when encountering the Monty Hall problem. The approach also increased correct probabilities for a new modification called the ‘new Monty Hall problem’, unlike two prominent alternative approaches to the original Monty Hall problem. The new Monty Hall problem also illustrates that humans can fail to recognize objectively strong evidence for a hypothesis if they neglect likelihoods.

Decades of research seek to understand how people form perceptions of risk by modeling either individual-level psychological processes or broader social and organizational mechanisms. Yet, little formal theoretical work has focused on the interaction of these 2 sets of factors. In this paper, I contribute to closing this gap by modifying a psychologically rich individual model of probabilistic reasoning to account for the transmission and collective emergence of risk perceptions. Using data from 357 individuals, I present experimental evidence in support of my main building assumptions and demonstrate the empirical validity of my model. Incorporating these results into an agent-based setting, I simulate over 1.5 billion social interactions to analyze the emergence of risk perceptions within organizations under different information frictions (i.e., limits on the availability and precision of social information). My results show that by focusing on information quality (rather than availability), groups and organizations can more effectively boost the accuracy of their emergent risk perceptions. This work offers researchers a formal framework to analyze the relationship between psychological and organizational factors in shaping risk perceptions.

Recent meta-analyses suggest that certain drugs act as cognitive enhancers and can increase attentional investment and performance even for healthy adults. The current review examines the potential of behavioral economics enhancers (BEEs) for similarly improving cognitive performance and judgments. Traditionally, behavioral economics theory has adopted a skeptical approach regarding the notion of whether individuals can overcome judgment biases through variables that increase cognitive effort. We focus mostly on the effects of two BEEs: incentivization and losses. Summarizing results from different meta-analyses, we find a small but robust positive effect size for BEEs, with comparable effect sizes to those found in studies of pharmacological cognitive enhancers.

Moral judgments are shaped by socialization and cultural heritage. Understanding how moral considerations vary across the globe requires the systematic development of moral stimuli for use in different cultures and languages. Focusing on Dutch populations, we adapted and validated two recent instruments for examining moral judgments: (1) the Moral Foundations Vignettes (MFVs) and (2) the Socio-Moral Image Database (SMID). We translated all 120 MFVs from English into Dutch and selected 120 images from SMID that primarily display moral, immoral, or neutral content. A total of 586 crowd-workers from the Netherlands provided over 38,460 individual judgments for both stimuli sets on moral and affective dimensions. For both instruments, we find that moral judgments and relationships between the moral foundations and political orientation are similar to those reported in the US, Australia, and Brazil. We provide the validated MFV and SMID images, along with associated rating data, to enable a broader study of morality.

Inclusion of a decoy alternative dominated by a target option, but not its competitor, typically leads to increased choice for the target over the competitor, known as the attraction effect. However, the reverse sometimes occurs, known as the repulsion effect. This research tested factors that moderate the repulsion effect in preferential choice scenarios with numerical attributes. Experiment 1 used a between-subjects design with a small set of consumer products and demonstrated robust repulsion effects that did not depend on the relative similarity of the decoy and target. Experiments 2 and 4 used a more powerful within-subjects design along with an expanded set of products and showed that repulsion effects were generally enhanced when the decoy and target had more similar attributes; however, the moderating effect of decoy–target similarity appeared to be fragile and sensitive to stimulus presentation factors. These findings provided mixed support for the hypothesis that the target is tainted by its proximity to the decoy. Experiments 3 and 5 tested whether the extremity of values on the attribute favoring the target moderates the repulsion effect. The results demonstrated that repulsion is more likely when all the alternatives have extremely high values on the target’s better attribute. Extremity of attribute values on the dimension favoring the target may result in a categorical assessment along that dimension and shift focus to the attribute favoring the competitor as one way to foster the repulsion effect.

We study why suffering a negative economic shock, i.e., a significant loss, may trigger a change in other-regarding behavior. We conjecture that people trade off concern for money with a conditional preference to follow social norms and that suffering a shock makes extrinsic motivation more salient, leading to more norm violation. This hypothesis is grounded on the premise that preferences are norm-dependent. We study this question experimentally: after administering losses on the earnings from a real-effort task, we analyze choices in prosocial and antisocial settings. To derive our predictions, we elicit social norms for each context analyzed in the experiments. We find evidence that shock increases deviations from norms.

The retrieval of past instances stored in memory can guide inferential choices and judgments. Yet, little process-level evidence exists that would allow a similar conclusion for preferential judgments. Recent research suggests that eye movements can trace information search in memory. During retrieval, people gaze at spatial locations associated with relevant information, even if the information is no longer present (the so-called ‘looking-at-nothing’ behavior). We examined eye movements based on the looking-at-nothing behavior to explore memory retrieval in inferential and preferential judgments. In Experiment 1, participants assessed their preference for smoothies with different ingredients, while the other half gauged another person’s preference. In Experiment 2, all participants made preferential judgments with or without instructions to respond as consistently as possible. People looked at exemplar locations in both inferential and preferential judgments, and both with and without consistency instructions. Eye movements to similar training exemplars predicted test judgments but not eye movements to dissimilar exemplars. These results suggest that people retrieve exemplar information in preferential judgments but that retrieval processes are not the sole determinant of judgments.

This study delves into the progression of nuclear war risk perceptions during the initial 6 months of the Ukraine war. It particularly investigated the influence of Italian media coverage changes and the affective tone of war representation. Utilizing a mixed-methods approach, two separate yet interconnected studies were conducted. The first study employed web scraping and keyword selection techniques to assess emotional language and quantify war-related content in the headlines of Italian online newspapers from March to July 2022. Results demonstrated a linear decrease in war-related news and an emotional shift, with a significant decrease in fear and an increase in joy noted between March and May. The second study examined nuclear war risk perceptions at an individual level, surveying a panel of 397 Italians at three distinct points during the same time frame. The findings revealed a similarity between the media’s affective tone and individuals’ affective risk perceptions. Analytic risk perception, in contrast, showed a linear decrease that matched the decline in war-related news volume. The study found preexisting individual differences, among women and older participants, to be significant determinants in shaping risk perception evolution. These groups exhibited higher initial risk perceptions and more resistance to change as the scenario unfolded. This research contributes to the existing body of work that underscores the media’s role in influencing risk perceptions by illuminating the relationship between media representation of the Ukraine war and individual-level affective risk perception. Furthermore, it highlights individual differences as significant moderators of risk perception change during a crisis.

Two preregistered web studies are presented that explore the impact of experience on the tendency to accept recommended defaults. In each of the 100 trials, participants (n = 180, n = 165) could accept a recommended default option or choose a less attractive prospect. The location of the options (left or right) was randomly determined before each trial. Both studies compared two conditions. Under Condition Dominant, the default option maximized participants’ payoff in all trials. Under Condition Protective, the default option protected the participants from rare losses and maximized expected return but decreased payoff in most trials. The results reveal a tendency to accept the default in Condition Dominant but the opposite tendency in Condition Protective. This pattern was predicted by assuming that in addition to promoting specific actions, the presentation of the default changes the set of feasible strategies, and choice between these strategies reflects reliance on small samples of past experiences.

Choices made in risky scenarios are considered fundamentally noisy because decisions have often been found to be inconsistent when repeated. Past measures of noise may, however, be confounded by the use of randomized contextual factors that are known to influence choice, in particular, the order of trials. In two experiments, we control trial order to test the extent to which inconsistent choice is attributable to changes in experimental context. Both tasks find strong evidence that trial order has no effect on choice consistency, indicating such experimental factors have little influence on behavior compared with internal noise. Choices also showed an increase in consistency across multiple repetitions, suggesting a fall in noise with experience, but this increase was not associated with any improvement in performance, with choices showing no greater adherence to either expected value or expected utility across repetitions. Instead, choices increasingly adhered to simplistic heuristic decision rules, possibly indicating greater reliance on such strategies as the tasks progressed. These results carry implications for a number of decision-making theories, including true-and-error models, rank-based methods, and strategy shift approaches.

In a ‘very close replication’ study using the same attributes as the original, Chandrashekar et al. (2021) report a failure to replicate some choose–reject problems documented in Shafir (1993). We find that several of the original attributes have changed their valence three decades later, and we compose new versions with updated attributes that fully replicate Shafir’s (1993) original findings. Despite their apparent exactitude, ‘very close replications’ across contexts or time, when stimuli may have changed their meaning or valence, can be highly misleading, further exacerbating replication concerns.

Communication is well-known to increase cooperation rates in social dilemma situations, but the exact mechanisms behind this remain largely unclear. This study examines the impact of communication on public good provisioning in an artefactual field experiment conducted with 216 villagers from small, rural communities in northern Namibia. In line with previous experimental findings, we observe a strong increase in cooperation when face-to-face communication is allowed before decision-making. We additionally introduce a condition in which participants cannot discuss the dilemma but talk to their group members about an unrelated topic prior to learning about the public good game. It turns out that this condition already leads to higher cooperation rates, albeit not as high as in the condition in which discussions about the social dilemma are possible. The setting in small communities also allows investigating the effects of pre-existing social relationships between group members and their interaction with communication. We find that both types of communication are primarily effective among socially more distant group members, which suggests that communication and social ties work as substitutes in increasing cooperation. Further analyses rule out better comprehension of the game and increased mutual expectations of one’s group members’ contributions as drivers for the communication effect. Finally, we discuss the role of personal and injunctive norms to keep commitments made during discussions.

Although diversity has often been proposed to improve group performance, its impact on group cooperation has largely been overlooked. This article uses a theoretical approach to examine the effects of diversity on group tasks in the context of the free-rider problem. We identified 3 kinds of diversity that have been commonly reported to improve a group’s performance: (1) ability, (2) cognitive style, and (3) information sources. Each type of diversity was formalized within an evolutionary simulation based on a foraging metaphor. The simulations were run under different environmental assumptions, covering complexity, costs for cooperation, cue redundancy, and cue compensatory level. Our results indicate that diversity in cognitive style and information sources generally increase cooperation. Both diversity factors also improve group members’ average outcome in non-compensatory environments. However, the outcome results are mixed in compensatory environments. We did not find robust and reliable effects of diversity in ability. Our study provides the first approach to modeling isolated diversity effects on group decision-making in the face of the free-rider problem. It may serve as a theoretical framework for future studies.

We often forego a larger future reward in order to obtain a smaller reward immediately, known as impatient intertemporal choice. The current study investigated the role of Pavlovian-to-instrumental transfer (PIT) as a mechanism contributing to impatient intertemporal choice, following a theoretical framework proposing that cues associated with immediate gratification trigger a Pavlovian approach response, interfering with goal-directed (instrumental) inhibitory behavior. We developed a paradigm in which participants first learned to make instrumental go/no-go responses in order to win rewards and avoid punishments. Next, they learned the associations between Pavlovian cues and rewards varying in amount and delay. Finally, we tested whether these (task-irrelevant) cues exerted transfer effects by influencing instrumental actions while participants again completed the go/no-go task. Across two experiments, Pavlovian cues associated with larger (versus smaller) and immediate (versus delayed) rewards were evaluated more positively, reflecting the successful acquisition of Pavlovian cue–outcome associations. These findings replicated the previously reported classical transfer effect of reward amount on instrumental behavior, as large (versus smaller) cues increased instrumental approach. In contrast, we found no evidence for the hypothesized transfer effects for reward delay, contrary to the proposed role of PIT in impatient intertemporal choice. These results suggest that although both reward amount and delay were important in the evaluation of cues, only the amount associated with cues influenced instrumental choice. We provide concrete suggestions for future studies, addressing instrumental outcome identity, competition between cue–amount and cue–delay associations, and individual differences in response to Pavlovian cues.