The heuristics-and-biases research program highlights reasons for expecting people to be poor intuitive forecasters. This article tests the power of a cognitive-debiasing training module (“CHAMPS KNOW”) to improve probability judgments in a four-year series of geopolitical forecasting tournaments sponsored by the U.S. intelligence community. Although the training lasted less than one hour, it consistently improved accuracy (Brier scores) by 6 to 11% over the control condition. Cognitive ability and practice also made largely independent contributions to predictive accuracy. Given the brevity of the training tutorials and the heterogeneity of the problems posed, the observed effects are likely to be lower-bound estimates of what could be achieved by more intensive interventions. Future work should isolate which prongs of the multipronged CHAMPS KNOW training were most effective in improving judgment on which categories of problems.

In recent years, many governments have shown a keen interest in “nudges” — approaches to law and policy that maintain freedom of choice, but that steer people in certain directions. Yet to date, there has been little evidence on whether citizens of various societies support nudges and nudging. We report the results of nationally representative surveys in six European nations: Denmark, France, Germany, Hungary, Italy, and the United Kingdom. We find strong majority support for nudges of the sort that have been adopted, or under serious consideration, in democratic nations. Despite the general European consensus, we find markedly lower levels of support for nudges in two nations: Hungary and Denmark. We are not, in general, able to connect support for nudges with distinct party affiliations.

The duration of ownership has been shown to increase the valuation of items that people currently own as well as items they have owned in the past, a phenomenon termed the “length-of-ownership effect.” We hypothesize that the duration of exposure to an item will foster increased pre-ownership attachment to an item and increased valuations in a manner similar to duration of actual ownership. We examine this effect in two experiments, both variations of the classic mug experiment. To induce different levels of exposure, we varied the amount of time that participants examined the auctioned item (i.e., coffee mugs) prior to participating in real dollar auctions. In the first study, participants bid in online English open bid auctions. In the second study, participants bid in first-price sealed bid auctions. In both cases of duration of physical contact positively influenced valuations (i.e., bid levels).

Previous studies suggest that choices are perceived as difficult as well as negatively emotion-laden when they tap into moral considerations. However, we propose that the involvement of moral issues and values can also facilitate decisions because people often insistently preclude them from trade-offs with other values. Because such values are treated as inviolable and absolute, they are called sacred values (e.g., Tetlock et al., 2000). Two experiments examined the influence of sacred values (measured by a recent self-report scale) and variation of trade-off type (taboo, tragic, routine trade-offs) on perceived decision difficulty and negative emotions. As hypothesized, decision difficulty and negative emotions show diverging patterns as a function of sacred values and trade-off types. When the decision situation involved two conflicting sacred values (i.e., tragic trade-off), people perceived the decision task as emotionally stressful and difficult. However, when the decision situation was associated with only one sacred value (i.e., taboo trade-off), people perceived the task as more negatively emotion-laden, but as easier to solve, compared to a situation not involving sacred values (i.e., routine trade-off). These findings suggest that reliance on sacred values may work as a heuristic.

Misinformation presents a significant societal problem. To measureindividuals’ susceptibility to misinformation and study its predictors,researchers have used a broad variety of ad-hoc item sets, scales, questionframings, and response modes. Because of this variety, it remains unknownwhether results from different studies can be compared (e.g., in meta-analyses).In this preregistered study (US sample; N = 2,622), we comparefive commonly used question framings (eliciting perceived headline accuracy,manipulativeness, reliability, trustworthiness, and whether a headline is realor fake) and three response modes (binary, 6-point and 7-point scales), usingthe psychometrically validated Misinformation Susceptibility Test (MIST). Wetest 1) whether different question framings and response modes yield similarresponses for the same item set, 2) whether people’s confidence in theirprimary judgments is affected by question framings and response modes, and 3)which key psychological factors (myside bias, political partisanship, cognitivereflection, and numeracy skills) best predict misinformation susceptibilityacross assessment methods. Different response modes and question framings yieldsimilar (but not identical) responses for both primary ratings and confidencejudgments. We also find a similar nomological net across conditions, suggestingcross-study comparability. Finally, myside bias and political conservatism werestrongly positively correlated with misinformation susceptibility, whereasnumeracy skills and especially cognitive reflection were less important(although we note potential ceiling effects for numeracy). We thus find moresupport for an “integrative” account than a “classicalreasoning” account of misinformation belief.

We present a motivational account of the impact of emotion on decision making, termed the feeling-is-for-doing approach. We first describe the psychology of emotion and argue for a need to be specific when studying emotion's impact on decision making. Next we describe what our approach entails and how it relates emotion, via motivation to behavior. Then we offer two illustrations of our own research that provide support for two important elements in our reasoning. We end with specifying four criteria that we consider to be important when studying how feeling guides our everyday doing.

The Food and Drug Administration (FDA) warned against administering over-the-counter cough and cold medicines to children under 2. This study evaluated whether experienced parents show poorer adherence to the FDA warning, as safe experiences are predicted to reduce the impact of warnings, and how adherence can be improved. Participants included 218 American parents (mean age: 29.98 (SD = 6.16), 82.9% female) with children age ≤ 2 who were aware of the FDA warning. We compared adherence among experienced (N=142; with other children > age 2) and inexperienced parents (N=76; only children ≤2). We also evaluated potential moderating variables (amount of warning-related information received, prevalence of side effects, trust in the FDA, frequency of coughs and colds, trust in drug packaging) and quantified the impact of amount of information. Logistic regression assessed the ability of experience alone, and experience combined with amount of information, to predict adherence. 53.3% of inexperienced but 28.4% of experienced parents were adherent (p = 0.0003). The groups did not differ on potential moderating variables. Adherence was 39.5% among experienced parents receiving “a lot of information”, but 15.4% for those receiving less (p = 0.002); amount of information did not affect adherence in inexperienced parents (p = 0.22) but uniquely predicted adherence compared to a model with experience alone (p = 0.0005). Experienced parents were also less likely to mistrust drug packaging (p = 0.03). Targeting FDA information to experienced parents, particularly via drug packaging, may improve their adherence.

Professional judges in traffic courts sentence many hundreds of offenders per year. Using 639 case files from archives, we compared the Matching Heuristic (MH) to compensatory, weighing algorithms (WM). We modeled and cross validated the models on different subsets of the data, and took several other methodological precautions such as allowing each model to select the optimal number of variables and ordering and weighing the variables in accordance to different logics. We did not reproduce the finding by Dhami (2003), who found the MH to be superior to a compensatory algorithm in modeling bail-granting decisions. These simulations brought out the inner logic of the two family of models, showing what combination of parameters works best. It remains remarkable that using only a fraction of the variables and combining them non-compensatorily, MH obtained nearly as good a fit as the weighing method.

This paper extends previous research showing that experienced difficulty ofrecall can influence evaluative judgments (e.g., Winkielman & Schwarz,2001) to a field study of university students rating a course. Studentscompleted a mid-course evaluation form in which they were asked to list either 2ways in which the course could be improved (a relatively easy task) or 10 waysin which the course could be improved (a relatively difficult task). Respondentswho had been asked for 10 critical comments subsequently rated the course morefavorably than respondents who had been asked for 2 critical comments. Aninternal analysis suggests that the number of critiques solicited provides aframe against which accessibility of instances is evaluated. The paper concludeswith a discussion of implications of the present results and possible directionsfor future research.

Often research in judgment and decision making requires comparison of multiple competing models. Researchers invoke global measures such as the rate of correct predictions or the sum of squared (or absolute) deviations of the various models as part of this evaluation process. Reliance on such measures hides the (often very high) level of agreement between the predictions of the various models and does not highlight properly the relative performance of the competing models in those critical cases where they make distinct predictions. To address this important problem we propose the use of pair-wise comparisons of models to produce more informative and targeted comparisons of their performance, and we illustrate this procedure with data from two recently published papers. We use Multidimensional Scaling of these comparisons to map the competing models. We also demonstrate how intransitive cycles of pair-wise model performance can signal that certain models perform better for a given subset of decision problems.

The group-diffusion effect is the tendency for people to judge themselves to be less likely to experience a negative outcome as the total number of people exposed to the threat increases — even when the probability of the outcome is explicitly presented (Yamaguchi, 1998). In Experiment 1 we replicated this effect for two health threat scenarios using a variant of Yamaguchi’s original experimental paradigm. In Experiment 2, we showed that people also judge themselves to be less likely to be selected in a lottery as the number of people playing the lottery increases. In Experiment 3, we showed that explicitly presenting the number of people expected to be selected eliminates the group-diffusion effect, and in Experiment 4 we showed that presenting the number expected to be affected by a health threat without presenting the total number exposed to the threat produces a reverse effect. We propose, therefore, that the group-diffusion effect is related to the ratio bias. Both effects occur when people make risk or likelihood judgments based on information presented as a ratio. The difference is that the group-diffusion effect occurs when the denominator of the relevant ratio is more salient than the numerator, while the ratio bias occurs when the numerator is more salient than the denominator.

This study directly tests the hypothesis that, at least within the domains of food and drink for Americans, the judgment of naturalness has more to do with the history of an object, that is the processes that it has undergone, as opposed to its material content. Individuals rate the naturalness and acceptability of a natural entity (water or tomato paste), that same entity with a first transformation in which a natural substance is added (or some part removed), and then a second transformation in which the natural additive is removed (or the removed part is replaced). The twice transformed entity is stipulated to be identical to the original natural entity, yet it is rated much less natural and less acceptable. It differs from the original entity only in its history (the reversed processes it has experienced). The twice transformed entity is also rated as less natural than the once-transformed entity, even though the former is identical to the original natural entity, and the latter is not. Therefore, naturalness depends heavily on the process-history of an entity.

In this paper, I trace the evolution of the aircraft cockpit as an example of the transformation of a probabilistic environment into an ecological hybrid, that is, an environment characterized by both probabilistic and deterministic features and elements. In the hybrid ecology, the relationships among correspondence and coherence strategies and goals and cognitive tactics on the continuum from intuition to analysis become critically important. Intuitive tactics used to achieve correspondence in the physical world do not work in the electronic world. Rather, I make the case that judgment and decision making in a hybrid ecology requires coherence as the primary strategy to achieve correspondence, and that this process requires a shift in tactics from intuition toward analysis.

In many sports contests, the equilibrium requires players to randomize across repeated rounds, i.e., exhibit no temporal predictability. Such sports data present a window into the (in)efficiency of random sequence generation in a natural competitive environment, where the decision makers (tennis players) are both highly experienced and incentivized compared to laboratory studies. I resolve a long-standing debate about whether professional players’ tennis serve directions are serially independent (Hsu, Huang & Tang, 2007) or not (Walker & Wooders, 2001) using a new dataset that is two orders of magnitude larger than those studies. I examine both between- and within-player determinants of the degree of serial (in)dependence. Evidence of the existence of significant serial dependence across serves is presented, even among players ranked Number 1 in the world. Furthermore, significant heterogeneity was found with respect to the strength of serial dependence and also its sign. A novel finding is that Number 1 and Number 2 ranked players tend to under-alternate on average, whereas in line with previous findings, the lower-ranked the players, the greater their tendency to over-alternate. Within-player analyses show that high-ranked players do not condition their randomization behavior on their opponent’s ranking. However, the under-alternation of top players would be consistent with a best-response to beliefs that the population of opponents over-alternates on average. Finally, the degree of observed serial dependence is not systematically related to other match variables proxying for match difficulty, fatigue, and psychological pressure.

We present the Concordant-Ranks (CR) strategy that decision makers use to quickly find an alternative that is proximate to an ideal alternative in a multi-attribute decision space. CR implies that decision makers prefer alternatives that exhibit concordant ranks between attribute values and attribute weights. We show that, in situations where the alternatives are equal in multi-attribute utility (MAU), minimization of the weighted Euclidean distance (WED) to an ideal alternative implies the choice of a CR alternative. In two experiments, participants chose among, as well as evaluated, alternatives that were constructed to be equal in MAU. In Experiment 1, four alternatives were designed in such a way that the choice of each alternative would be consistent with one particular choice strategy, one of which was the CR strategy. In Experiment 2, participants were presented with a CR alternative and a number of arbitrary alternatives. In both experiments, participants tended to choose the CR alternative. The CR alternative was on average evaluated as more attractive than other alternatives. In addition, measures of WED, between given alternatives and the ideal alternative, by and large agreed with the preference order for choices and attractiveness evaluations of the different types of alternatives. These findings indicate that both choices and attractiveness evaluations are guided by proximity of alternatives to an ideal alternative.

Most people are caring and will exert great effort to rescue individual victims whose needy plight comes to their attention. These same good people, however, often become numbly indifferent to the plight of individuals who are “one of many” in a much greater problem. Why does this occur? The answer to this question will help us answer a related question that is the topic of this paper: Why, over the past century, have good people repeatedly ignored mass murder and genocide? Every episode of mass murder is unique and raises unique obstacles to intervention. But the repetitiveness of such atrocities, ignored by powerful people and nations, and by the general public, calls for explanations that may reflect some fundamental deficiency in our humanity — a deficiency that, once identified, might possibly be overcome. One fundamental mechanism that may play a role in many, if not all, episodes of mass-murder neglect involves the capacity to experience affect, the positive and negative feelings that combine with reasoned analysis to guide our judgments, decisions, and actions. I shall draw from psychological research to show how the statistics of mass murder or genocide, no matter how large the numbers, fail to convey the true meaning of such atrocities. The reported numbers of deaths represent dry statistics, “human beings with the tears dried off,” that fail to spark emotion or feeling and thus fail to motivate action. Recognizing that we cannot rely only upon our moral feelings to motivate proper action against genocide, we must look to moral argument and international law. The 1948 Genocide Convention was supposed to meet this need, but it has not been effective. It is time to examine this failure in light of the psychological deficiencies described here and design legal and institutional mechanisms that will enforce proper response to genocide and other forms of mass murder.

Investors, like any decision maker, feel regret when they compare the outcome of an investment with what the outcome would have been had they invested differently. We argue and show that this counterfactual comparison process is most likely to take place when the decision maker’s expectations are violated. Across five scenario experiments we found that decision makers were influenced only by forgone investment outcomes when the realized investment fell short of the expected result. However, when their investments exceeded prior expectations, the effect of foregone investment on regret disappeared. In addition, Experiment 4 found that individual differences in the need to maximize further moderated the effects of their expectations, such that maximizers always take into account the forgone investment. The final experiment found that when probed to make counterfactual comparisons, also investments that exceed expectations may lead to regret. Together these experiments reveal insights into the comparative processes leading to decision regret.

Two psychological sources of uncertainty bear implications for judgment and decision-making: external uncertainty is seen as stemming from properties of the world, whereas internal uncertainty is seen as stemming from lack of knowledge. The apparent source of uncertainty can be conveyed through linguistic markers, such as the pronoun of probability phrases (e.g., I am uncertain vs. It is uncertain). Here, we investigated whether and when speakers use different pronoun subjects as such linguistic markers (Exp. 1 and 2) and what hearers infer from them (Exp. 3 and 4). Speakers more often described higher probabilities and knowable outcomes with internal probability phrases. In dialogue, speakers mirrored the source of their conversational partner. Markers of the source had a main effect or interacted with the probability conveyed and speaker expertise to shape the judgments and decisions of hearers. For example, experts voicing an internal probability phrase were judged as more knowledgeable than experts using an external probability phrase whereas the result was the opposite for lay speakers. We discuss how these findings inform our understanding of subjective uncertainty and uncertainty communication theories.

Past research has shown that people consistently believe that others are more easily manipulated by external influences than they themselves are—a phenomenon called the “third-person effect” (Davison, 1983). The present research investigates whether support for public policies aimed at changing behavior using incentives and other decision “nudges” is affected by this bias. Across two studies, we phrased justification for public policy initiatives using either the second- or third-person plural. In Study 1, we found that support for policies is higher when their justification points to people in general rather than the general “you”, and in Study 2 we found that this former phrasing also improves support compared to a no-justification control condition. Policy support is mediated by beliefs about the likelihood of success of the policies (as opposed to beliefs about the policies’ unintended consequences), and, in the second-person condition, is inversely related to a sense of personal agency. These effects suggest that the third-person effect holds true for nudge-type and incentive-based public policies, with implications for their popular support.

We conduct a laboratory experiment to investigate whether the rebate and matching subsidy schemes cause crowding-out or crowding-in effects (reductions or increases in amount donated) on individual net donations. We find that when the rebate subsidy scheme is implemented, it does not result in crowding-out or crowding-in effects on individual net donations. However, when the matching subsidy scheme is implemented, it encourages individuals to donate more and generates crowding-in effects on individual net donations.