# Judgment and Decision Making

Published by Society for Judgment and Decision Making
Online ISSN: 1930-2975
Publications
Article
Some people find it more difficult to delay rewards than others. In three experiments, we tested a "future self-continuity" hypothesis that individual differences in the perception of one's present self as continuous with a future self would be associated with measures of saving in the laboratory and everyday life. Higher future self-continuity (assessed by a novel index) predicted reduced discounting of future rewards in a laboratory task, more matches in adjectival descriptions of present and future selves, and greater lifetime accumulation of financial assets (even after controlling for age and education). In addition to demonstrating the reliability and validity of the future self-continuity index, these findings are consistent with the notion that increased future self-continuity might promote saving for the future.

Article
Affective forecasting skills have important implications for decision making. However, recent research suggests that immune neglect - the tendency to overlook coping strategies that reduce future distress - may lead to affective forecasting problems. Prior evidence for immune neglect has been indirect. More direct evidence and a deeper understanding of immune neglect are vital to informing the design of future decision-support interventions. In the current study, young adults (N = 325) supplied predicted, actual, and recollected reactions to an emotionally-evocative interpersonal event, Valentine's Day. Based on participants' qualitative descriptions of the holiday, a team of raters reliably coded the effectiveness of their coping strategies. Supporting the immune neglect hypothesis, participants overlooked the powerful role of coping strategies when predicting their emotional reactions. Immune neglect was present not only for those experiencing the holiday negatively (non-daters) but also for those experiencing it positively (daters), suggesting that the bias may be more robust than originally theorized. Immune neglect was greater for immediate emotional reactions than more enduring reactions. Further, immune neglect was conspicuously absent from recollected emotional reactions. Implications for decision-support interventions are discussed.

Article
When making decisions that involve tradeoffs between the quality and timing of desirable outcomes, people consistently discount the value of future outcomes. A puzzling finding regarding such decisions is the extremely high rate at which people discount future monetary outcomes. Most economists would argue that decision-makers should only turn down rates of return that are lower than those available to them elsewhere. Yet the vast majority of studies find discount rates that are significantly higher than market interest rates (Frederick et al., 2002). Here we ask whether a lack of knowledge about the normative strategy can explain high discount rates. In an initial experiment, we find that nearly half of subjects do not spontaneously cite elements of the normative strategy when asked how people should make intertemporal monetary decisions. In two follow-up experiments, we find that after subjects read a "financial guide" detailing the normative strategy, discount rates declined by up to 85%, but were still higher than market interest rates. This decline persisted, though attenuated, for at least one month. In a final experiment, we find that peer-generated advice influences discount rates in a similar manner to "expert" advice, and that arguments focusing on normative considerations are at least as effective as others. These studies show that part of the explanation for high discount rates is a lack of knowledge regarding the normative strategy, and quantify how much discount rates are reduced in response to normative arguments. Given the high level of discounting that remains, however, there are other contributing factors to high discount rates that remain to be quantified.

Article
Auctions, normally considered as devices facilitating trade, also provide a way to probe mechanisms governing one's valuation of some good or action. One of the most intriguing phenomena in auction behavior is the winner's curse - the strong tendency of participants to bid more than rational agent theory prescribes, often at a significant loss. The prevailing explanation suggests that humans have limited cognitive abilities that make estimating the correct bid difficult, if not impossible. Using a series of auction structures, we found that bidding approaches rational agent predictions when participants compete against a computer. However, the winner's curse appears when participants compete against other humans, even when cognitive demands for the correct bidding strategy are removed. These results suggest the humans assign significant future value to victories over human but not over computer opponents even though such victories may incur immediate losses, and that this valuation anomaly is the origin of apparently irrational behavior.

Article
Humans and other animals are idiosyncratically sensitive to risk, either preferring or avoiding options having the same value but differing in uncertainty. Many explanations for risk sensitivity rely on the non-linear shape of a hypothesized utility curve. Because such models do not place any importance on uncertainty per se, utility curve-based accounts predict indifference between risky and riskless options that offer the same distribution of rewards. Here we show that monkeys strongly prefer uncertain gambles to alternating rewards with the same payoffs, demonstrating that uncertainty itself contributes to the appeal of risky options. Based on prior observations, we hypothesized that the appeal of the risky option is enhanced by the salience of the potential jackpot. To test this, we subtly manipulated payoffs in a second gambling task. We found that monkeys are more sensitive to small changes in the size of the large reward than to equivalent changes in the size of the small reward, indicating that they attend preferentially to the jackpots. Together, these results challenge utility curve-based accounts of risk sensitivity, and suggest that psychological factors, such as outcome salience and uncertainty itself, contribute to risky decision-making.

Article
We compare four different risk-taking propensity measures on their ability to describe and to predict actual risky behavior in the domain of health. The risk-taking propensity measures we compare are: (1) a general measure of risk-taking propensity derived from a one-item survey question (Dohmen et al., 2011), (2) a risk aversion index calculated from a set of incentivized monetary gambles (Holt & Laury, 2002), (3) a measure of risk taking derived from an incentive compatible behavioral task-the Balloon Analog Risk Task (Lejuez et al., 2002), and (4) a composite score of risk-taking likelihood in the health domain from the Domain-Specific Risk Taking (DOSPERT) scale (Weber et al., 2002). Study participants are 351 clients of health centers around Witbank, South Africa. Our findings suggest that the one-item general measure is the best predictor of risky health behavior in our population, predicting two out of four behaviors at the 5% level and the remaining two behaviors at the 10% level. The DOSPERT score in the health domain performs well, predicting one out of four behaviors at the 1% significance level and two out of four behaviors at the 10% level, but only if the DOSPERT instrument contains a hypothetical risk-taking item that is similar to the actual risky behavior being predicted. Incentivized monetary gambles and the behavioral task were unrelated to actual health behaviors; they were unable to predict any of the risky health behaviors at the 10% level. We provide evidence that this is not because the participants had trouble understanding the monetary trade-off questions or performed poorly in the behavioral task. We conclude by urging researchers to further test the usefulness of the one-item general measure, both in explaining health related risk-taking behavior and in other contexts.

Article
Although theories from economics and evolutionary biology predict that one's age, health, and survival probability should be associated with one's subjective discount rate (SDR), few studies have empirically tested for these links. Our study analyzes in detail how the SDR is related to age, health, and survival probability, by surveying a sample of individuals in townships around Durban, South Africa. In contrast to previous studies, we find that age is not significantly related to the SDR, but both physical health and survival expectations have a U-shaped relationship with the SDR. Individuals in very poor health have high discount rates, and those in very good health also have high discount rates. Similarly, those with expected survival probability on the extremes have high discount rates. Therefore, health and survival probability, and not age, seem to be predictors of one's SDR in an area of the world with high morbidity and mortality.

Article
People report themselves to be above average on simple tasks and below average on difficult tasks. This paper proposes an explanation for this effect that is simpler than prior explanations. The new explanation is that people conflate relative with absolute evaluation, especially on subjective measures. The paper then presents a series of four studies that test this conflation explanation. These tests distinguish conflation from other explanations, such as differential weighting and selecting the wrong referent. The results suggest that conflation occurs at the response stage during which people attempt to disambiguate subjective response scales in order to choose an answer. This is because conflation has little effect on objective measures, which would be equally affected if the conflation occurred at encoding.

Article
Together with his long-time colleague Daniel Kahneman, Amos Tversky, provided the intellectual infrastructure for contemporary behavioral law and economics. Prospect theory undermines the Coase Theorem, which is the bedrock of traditional law and economics; and the heuristics and biases research questions the fundamental idea of a rational self-interested decisionmaker, which is also challenged by subsequent studies of the role of affect in judgment and decisionmaking.

Article
According to prospect theory, people overweight low probability events and underweight high probability events. Several recent papers (notably, Hertwig, Barron, Weber \& Erev, 2004) have argued that although this pattern holds for description-based'' decisions, in which people are explicitly provided with probability distributions over potential outcomes, it is actually reversed in experience-based'' decisions, in which people must learn these distributions through sampling. We reanalyze the data of Hertwig et al. (2004) and present a replication to determine the extent to which their phenomenon can be attributed to sampling error (a statistical rather than psychological phenomenon) versus underestimation of rare events (i.e., judgmental bias) versus actual underweighting of judged probabilities. We find that the apparent reversal of prospect theory in decisions from experience can be attributed almost entirely to sampling error, and are consistent with prospect theory and the two-stage model of decision under uncertainty (Fox \& Tversky, 1998).

Article
The current study is based on a field study of the 2006 Israel-Lebanon war that was conducted in two waves, the first two weeks after the end of the war, and the second 18 months later (2008). The purpose of the study was to examine recalled emotions and perceived risks induced by manipulation using a short videoclip that recalled the sounds of the alarms and the sights of the missile attacks during the war. Before filling in the study questionnaire in 2008, the experimental group watched a short videoclip recalling the events of the war. The control group did not watch the video before filling in the questionnaire. Using the data provided by questionnaires, we analyzed the effect of recalled emotions on perceived risks in two different regions in Israel: the northern region, which was under missile attack daily during the war, and the central region, which was not under missile attacks. The videoclip had a strong effect on the level of recalled emotions in both regions, but it did not affect risk judgments. The results of the analytical framework in the northern region support both the valence approach, in which negative emotion increases pessimism about risk (Johnson \& Tversky, 1983), and the modified appraisal tendency theory, which implies different effects for different emotions (Lerner \& Keltner, 2000). The current study emphasizes the effects of recalled emotion in the context of the 2006 Israel-Lebanon war on perceived risks among those in the northern region who were under direct attack compared to those who were not directly exposed to the war. Understanding people's responses to stressful events is crucial, not only when these events take place but also over time, since media-induced emotions can influence appraisals and decisions regarding public policies.

Article
Oppenheimer and Monin (2009) recently found that subjectively rare events are taken to indicate a longer preceding sequence of unobserved trials than subjectively common events, an effect which they refer to as the retrospective gambler's fallacy. The current paper extends this idea to the situation where participants judge the likelihood of streak continuation. Participants were told about a streak produced by a random process (coin flips) or human performance (basketball shots), and either predicted the next outcome or inferred the immediately preceding outcome. For the coin scenarios, participants tended to expect streak termination -- the gambler's fallacy --- and this effect was the same for predictions and retrospective inferences. In the basketball scenarios, no overall bias was found in either prospective or retrospective judgments. The results support Oppenheimer and Monin's suggestion that reconstruction of the past entails the same heuristics as prediction of the future; they also support the idea that the nature of the data-generating process is a key determinant of whether people fall into the gambler's fallacy. It is suggested that the term retrospective gambler's fallacy be used to describe situations where a streak is taken to indicate that the preceding unobserved outcome was of the opposite type, and that the phenomenon discovered by Oppenheimer and Monin be referred to as retrospective representativeness, or a retrospective belief in the law of small numbers.

Article
One major challenge to behavioral decision research is to identify the cognitive processes underlying judgment and decision making. Gloeckner (2009) has argued that, compared to previous methods, process models can be more efficiently tested by simultaneously analyzing choices, decision times, and confidence judgments. The Multiple-Measure Maximum Likelihood (MM-ML) strategy classification method was developed for this purpose and implemented as a ready-to-use routine in STATA, a commercial package for statistical data analysis. In the present article, we describe the implementation of MM-ML in R, a free package for data analysis under the GNU general public license, and we provide a practical guide to application. We also provide MM-ML as an easy-to-use R function. Thus, prior knowledge of R programming is not necessary for those interested in using MM-ML.

Article
Hypotheses about decision processes are often formulated qualitatively and remain silent about the interplay of decision, memorial, and other cognitive processes. At the same time, existing decision models are specified at varying levels of detail, making it difficult to compare them. We provide a methodological primer on how detailed cognitive architectures such as ACT-R allow remedying these problems. To make our point, we address a controversy, namely, whether noncompensatory or compensatory processes better describe how people make decisions from the accessibility of memories. We specify 39 models of accessibility-based decision processes in ACT-R, including the noncompensatory recognition heuristic and various other popular noncompensatory and compensatory decision models. Additionally, to illustrate how such models can be tested, we conduct a model comparison, fitting the models to one experiment and letting them generalize to another. Behavioral data are best accounted for by race models. These race models embody the noncompensatory recognition heuristic and compensatory models as a race between competing processes, dissolving the dichotomy between existing decision models.

Article
Individual differences in cognitive abilities and skills can predict normatively superior and logically consistent judgments and decisions. The current experiment investigates the processes that mediate individual differences in risky choices. We assessed working memory span, numeracy, and cognitive impulsivity and conducted a protocol analysis to trace variations in conscious deliberative processes. People higher in cognitive abilities made more choices consistent with expected values; however, expected-value choices rarely resulted from expected-value calculations. Instead, the cognitive ability and choice relationship was mediated by the number of simple considerations made during decision making --- e.g., transforming probabilities and considering the relative size of gains. Results imply that, even in simple lotteries, superior risky decisions associated with cognitive abilities and controlled cognition can reflect metacognitive dynamics and elaborative heuristic search processes, rather than normative calculations. Modes of cognitive control (e.g., dual process dynamics) and implications for process models of risky decision-making (e.g., priority heuristic) are discussed.

Article
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.

Article
Schelling (1969, 1971a,b, 1978) observed that macro-level patterns do not necessarily reflect micro-level intentions, desires or goals. In his classic model on neighborhood segregation which initiated a large and influential literature, individuals with no desire to be segregated from those who belong to other social groups nevertheless wind up clustering with their own type. Most extensions of Schelling's model have replicated this result. There is an important mismatch, however, between theory and observation, which has received relatively little attention. Whereas Schelling-inspired models typically predict large degrees of segregation starting from virtually any initial condition, the empirical literature documents considerable heterogeneity in measured levels of segregation. This paper introduces a mechanism that can produce significantly higher levels of integration and, therefore, brings predicted distributions of segregation more in line with real-world observation. As in the classic Schelling model, agents in a simulated world want to stay or move to a new location depending on the proportion of neighbors they judge to be acceptable. In contrast to the classic model, agents' classifications of their neighbors as acceptable or not depend lexicographically on recognition first and group type (e.g., ethnic stereotyping) second. The FACE-recognition model nests classic Schelling: When agents have no recognition memory, judgments about the acceptability of a prospective neighbor rely solely on his or her group type (as in the Schelling model). A very small amount of recognition memory, however, eventually leads to different classifications that, in turn, produce dramatic macro-level effects resulting in significantly higher levels of integration. A novel implication of the FACE-recognition model concerns the large potential impact of policy interventions that generate modest numbers of face-to-face encounters with members of other social groups.

Article
Very small but cumulated decreases in food intake may be sufficient to erase obesity over a period of years. We examine the effect of slight changes in the accessibility of different foods in a pay-by-weight-of-food salad bar in a cafeteria serving adults for the lunch period. Making a food slightly more difficult to reach (by varying its proximity by about 10 inches) or changing the serving utensil (spoon or tongs) modestly but reliably reduces intake, in the range of 8-16%. Given this effect, it is possible that making calorie-dense foods less accessible and low-calorie foods more accessible over an extended period of time would result in significant weight loss.

Article
Judgments and decisions under uncertainty are frequently linked to a prior sequential search for relevant information. In such cases, the subject has to decide when to stop the search for information. Evidence accumulation models from social and cognitive psychology assume an active and sequential information search until enough evidence has been accumulated to pass a decision threshold. In line with such theories, we conceptualize the evidence threshold as the desired level of confidence'' (DLC) of a person. This model is tested against a fixed stopping rule (one-reason decision making) and against the class of multi-attribute information integrating models. A series of experiments using an information board for horse race betting demonstrates an advantage of the proposed model by measuring the individual DLC of each subject and confirming its correctness in two separate stages. In addition to a better understanding of the stopping rule (within the narrow framework of simple heuristics), the results indicate that individual aspiration levels might be a relevant factor when modelling decision making by task analysis of statistical environments.

Article
Judgments of naturalness of foods tend to be more influenced by the process history of a food, rather than its actual constituents. Two types of processing of a natural'' food are to add something or to remove something. We report in this study, based on a large random sample of individuals from six countries (France, Germany, Italy, Switzerland, UK and USA) that additives are considered defining features of what makes a food not natural, whereas subtractives'' are almost never mentioned. In support of this, skim milk (with major subtraction of fat) is rated as more natural than whole milk with a small amount of natural vitamin D added. It is also noted that additives'' is a common word, with a synonym reported by a native speaker in 17 of 18 languages, whereas subtractive'' is lexicalized in only 1 of the 18 languages. We consider reasons for additivity dominance, relating it to omission bias, feature positive bias, and notions of purity.

Article
Contrary to the common belief that more information is always better, Gigerenzer et al.\ (1999) showed that simple decision strategies which rely on little information can be quite successful. The success of simple strategies depends both on bets about the structure of the environment and on the core capacities of the human mind, such as recognition memory (Gigerenzer, 2004). However, the interplay between the environment and the mind's core capacities has rarely been precisely modeled. We illustrate how these environment-mind interactions could be formally modeled within the cognitive architecture ACT-R (J. R. Anderson et al., 2004). ACT-R is an integrated theory of mind that is tuned to the statistical structure of the environment, and it can account for a variety of phenomena such as learning, problem solving, and decision making. Here, we focus on studying decision strategies and show how the success of theses strategies in particular environments depends on characteristics of core cognitive capacities, such as recognition and short term memory.

Article
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 \textit{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.

Article
Previous research has demonstrated that consistency between people's behavior and their dispositions has predictive validity for judgments of regret. Research has also shown that differences in the personality variable of action orientation can influence ability to regulate negative affect. The present set of studies was designed to investigate how both consistency factors and action-state personality orientation influence judgments of regret. In Study 1, we used a recalled life event to provide a situation in which the person had experienced either an action or inaction. Individuals with an action orientation experienced more regret for situations involving inaction (staying home) than situations involving action (going out). State-oriented individuals, however, maintained high levels of regret and did not differ in their regret ratings across either the action or inaction situations. In Study 2, participants made realistic choices involving either an action or inaction. Our findings revealed the same pattern of results: action-oriented individuals who chose an option that involved not acting (inaction) had more regret that individuals who chose an option that involved acting (action). State-oriented individuals experienced high levels of regret regardless of whether they chose to act or not to act.

Article
Are people willing to gamble more for themselves than what they deem reasonable for others? We addressed this question in a simplified computer gambling task in which subjects chose from a set of 10 cards. Subjects selected one card at a time after being instructed that 9 cards were good (win a dollar per card) and one was really bad (lose all the money and end the game). Subjects could stop playing at any time to collect their winnings. Some subjects played the game, others observed a confederate. Both groups took risks beyond what was rational (i.e., 5 cards) but \textit{actors} were riskier than \textit{observers}. The actor/observer asymmetry occurred even after controlling for monetary outcome (i.e., having observers win prizes) and after controlling for how the question was framed (i.e., asking observers what they themselves \textit{would} do as opposed to what the confederate \textit{should} do). We discuss these results in relation to theories of decision making that emphasize separate contributions of rational and experiential systems.

Article
People live in a world in which they are surrounded by potential disgust elicitors such as used'' chairs, air, silverware, and money as well as excretory activities. People function in this world by ignoring most of these, by active avoidance, reframing, or adaptation. The issue is particularly striking for professions, such as morticians, surgeons, or sanitation workers, in which there is frequent contact with major disgust elicitors. In this study, we study the adaptation'' process to dead bodies as disgust elicitors, by measuring specific types of disgust sensitivity in medical students before and after they have spent a few months dissecting a cadaver. Using the Disgust Scale, we find a significant reduction in disgust responses to death and body envelope violation elicitors, but no significant change in any other specific type of disgust. There is a clear reduction in discomfort at touching a cold dead body, but not in touching a human body which is still warm after death.

Article
While previous research has found that children make more risky decisions than their parents, little is known about the developmental trajectory for the ability to make advantageous decisions. In a sample of children, 5--11 years old, we administered a new risky decision making task in which the relative expected value (EV) of the risky and riskless choice options was varied over trials. Younger children (age 5--7) showed significantly less responsiveness to EV differences than their parents on both trials involving risky gains and trials involving risky losses. For older children (age 8--11) this deficit was smaller overall but was greater on loss trials than on gain trials. Children of both ages made more risky choices than adults when risky choices were disadvantageous. We further analyzed these results in terms of children's ability to utilize probability and outcome information, and discussed them in terms of developing brain structures vital for decision making under uncertainty.

Article
The authors review their own empirical work inspired by the adaptive toolbox metaphor. The review examines factors influencing strategy selection and execution in multi-attribute inference tasks (e.g., information costs, time pressure, memory retrieval, dynamic environments, stimulus formats, intelligence). An emergent theme is the re-evaluation of contingency model claims about the elevated cognitive costs of compensatory in comparison with non-compensatory strategies. Contrary to common assertions about the impact of cognitive complexity, the empirical data suggest that manipulated variables exert their influence at the meta-level of deciding how to decide (i.e., which strategy to select) rather than at the level of strategy execution. An alternative conceptualisation of strategy selection, namely threshold adjustment in an evidence accumulation model, is also discussed and the difficulty in distinguishing empirically between these metaphors is acknowledged.

Article
Ninety-eight Australian students participated in a functional replication of a study published by Dijksterhuis et al.\ (2006). The results indicated that unconscious thought does not necessarily lead to better normative decision making performance than conscious thought, which is contrary to the results found in Dijksterhuis et al. Since other studies showed a positive, though statistically not significant, effect for unconscious thought, a meta-analysis comprising a total of 17 experiments was conducted. It suggests that there is little evidence for an advantage to normative decision making using unconscious thought. However, a discussion of potential moderators shows that further study would help to identify situations in which unconscious thought is truly helpful and those in which it is not.

Article
This paper proposes a revised version of the original Domain-Specific Risk-Taking (DOSPERT) scale developed by Weber, Blais, and Betz (2002) that is shorter and applicable to a {broader range of ages, cultures, and educational levels}. It also provides a French translation of the revised scale. Using multilevel modeling, we investigated the risk-return relationship between apparent risk taking and risk perception in 5 risk domains. The results replicate previously noted differences in reported degree of risk taking and risk perception at the mean level of analysis. The multilevel modeling shows, more interestingly, that within-participants variation in risk taking across the 5 content domains of the scale was about 7 times as large as between-participants variation. We discuss the implications of our findings in terms of the person-situation debate related to risk attitude

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Article
The present research aimed to test the role of mood in the Iowa Gambling Task (IGT; Bechara et al., 1994). In the IGT, participants can win or lose money by picking cards from four different decks. They have to learn by experience that two decks are overall advantageous and two decks are overall disadvantageous. Previous studies have shown that at an early stage in this card-game, players begin to display a tendency towards the advantageous decks. Subsequent research suggested that at this stage, people base their decisions on conscious gut feelings (Wagar \& Dixon, 2006). Based on empirical evidence for the relation between mood and cognitive processing-styles, we expected and consistently found that, compared to a negative mood state, reported and induced positive mood states increased this early tendency towards advantageous decks. Our results provide support for the idea that a positive mood causes stronger reliance on affective signals in decision-making than a negative mood.

Article
(from the introduction) Intuition and affect have been neglected topics in the literature on human judgment and decision making for a long time. Judgmental processes involved in risk perception and decision making have traditionally been conceptualized as cognitive in nature, being based upon a rational and deliberate evaluation of the alternatives at hand. This picture started to change in the early 1980s when decision researchers looked beyond rational, deliberate, and cognitive processes and began to investigate intuitive --- as opposed to deliberate --- and emotional --- as opposed to cognitive --- aspects of decision making. In sum, decision research has seen a proliferation of approaches that look beyond rational, deliberate, and purely cognitive processes in decision making and investigate intuitive and emotional judgments in this area. This seemed like a good point in time to reflect the state of this emerging field in a special issue that addresses the question of how intuition and affect are related to each other and how they shape risk perception and decision making. This special issue is the result of a workshop that was held at the University of Bergen in November, 2006.

Article
Knowing what event precipitated a client's abnormal behaviors makes the client appear more normal than if the event is not known (Meehl, 1973). Does such knowledge also influence judgments of the need for psychological treatment, and if so, does it matter whether the precipitating event was inside or outside the client's control? We presented undergraduates with cases of hypothetical clients exhibiting abnormal behaviors and manipulated whether they were also told of a precipitating event explaining those behaviors. Knowing the precipitant significantly reduced perceptions of clients' need for treatment, but only when the precipitating event was outside the client's control. These findings call into question the notion that it need always be beneficial for an outside reasoner to uncover the root cause of a client's psychological problems, particularly when the root cause is still unknown to the client. The rationality of the effect and additional implications for decision-making are discussed.

Article
Some decision situations are so objectionable or repugnant that people refuse to make a choice. This paper seeks to better understand taboo responses, and to distinguish choices that are truly taboo from those that are merely difficult or confusing. Using 22 scenarios that describe potentially taboo issues, Experiment 1 explores reasons for disapproval of the scenarios. We measure a large number of possible reasons for disapproval and a variety of preference responses (including willingness to accept), in order to test for subtleties in taboo responses. We also test cognitive and affective responses to the scenarios. Experiment 2 further explores the interaction, found in Experiment 1, between affective and cognitive factors. Taken as a whole, our results show that people are able to indicate their disapproval consistently across a variety of preference elicitation methods, that their disapproval is better understood as an attitude measure than as an economic valuation (even when the measure is in monetary terms), and that taboo responses are driven primarily by affect.

Article
People overestimate their affective reactions to future events and decisions --- a phenomenon that has been termed impact bias.'' Evidence suggests that completing a diary detailing events contemporaneous with the focal one de-biases judgments of affect. It is generally assumed that this is because diary completion helps people to realize that they will be distracted from the focal event. However, there is another possibility: de-biasing may occur because diary completion interferes with the processing responsible for the bias. In a first experiment, we showed that diary completion also lowers affect associated with past decisions. In a second experiment, we showed that solving anagrams has the same effect. A third experiment demonstrates that this is not because affect judgments are influenced by mood changes brought about by solving anagrams. Indeed, monitoring moods lowered affect in the same way as diary completion. It appears that cognitive tasks of any sort interfere with the processing required by judgments of affect.

Article
Environmental events such as natural disasters may influence the public's affective reactions and decisions. Shortly after the 2004 Tsunami disaster we assessed how affect elicited by thinking about this disaster influenced risk perceptions and future time perspective in Swedish undergraduates not directly affected by the disaster. An experimental manipulation was used to increase the salience of affect associated with the disaster. In Study 1 we found that participants reminded about the tsunami had a sense that their life was more finite and included fewer opportunities than participants in the control condition (not reminded about the tsunami). In Study 2 we found similar effects for risk perceptions. In addition, we showed that manipulations of ease-of-thought influenced the extent to which affect influenced these risk perceptions, with greater ease of thoughts being associated with greater perceived risks.

Article
Often to the detriment of human decision making, people are prone to an impact bias when making affective forecasts, overestimating the emotional consequences of future events. The cognitive processes underlying the impact bias, and methods for correcting it, have been debated and warrant further exploration. In the present investigation, we examined both individual differences and contextual variables associated with cognitive processing in affective forecasting for an election. Results showed that the perceived importance of the event and working memory capacity were both associated with an increased impact bias for some participants, whereas retrieval interference had no relationship with bias. Additionally, an experimental manipulation effectively reduced biased forecasts, particularly among participants who were most distracted thinking about peripheral life events. These findings have theoretical implications for understanding the impact bias, highlight the importance of individual differences in affective forecasting, and have ramifications for future decision making research. The possible functional role of the impact bias is discussed within the context of evolutionary psychology.

Article
Three experiments demonstrate how the processing of negations is contingent on the evaluation context in which the negative information is presented. In addition, the strategy used to process the negations induced different affective reactions toward the stimuli, leading to inconsistency of preference. Participants were presented with stimuli described by either stating the presence of positive features (explicitly positive alternative) or negating the presence of negative features (non-negative alternative). Alternatives were presented for either joint (JE) or separate evaluation (SE). Experiment 1 showed that the non-negative stimuli were judged less attractive than the positive ones in JE but not in SE. Experiment 2 revealed that the non-negative stimuli induced a less clear and less positive feeling when they were paired with explicitly positive stimuli rather than evaluated separately. Non-negative options were also found less easy to judge than the positive ones in JE but not in SE. Finally, Experiment 3 showed that people process negations using two different models depending on the evaluation mode. Through a memory task, we found that in JE people process the non-negative attributes as negations of negative features, whereas in SE they directly process the non-negative attributes as positive features.

Article
Three experiments investigated individuals' preferences and affective reactions to negative life experiences. Participants had a more intense negative affective reaction when they were exposed to a highly negative life experience than when they were exposed to two negative events: a highly negative and a mildly negative life event. Participants also chose the situation containing two versus one negative event. Thus, more negative events were better'' when the events had different affective intensities. When participants were exposed to events having similar affective intensities, however, two negative events produced a more intense negative affective reaction. In addition, participants chose the situation having one versus two negative life experiences. Thus, more negative events were worse'' when the events had similar affective intensities. These results are consistent with an averaging/summation (A/S) model and delineate situations when more'' negative life events are better'' and when more'' negative life events are worse.'' Results also ruled out several alternative interpretations including the peak-end rule and mental accounting interpretations. % check keywords

Article
By manipulating the scale in graphs, this study demonstrated a new evaluation bias caused by attribute salience in graphical representations. That is, (de)compressing the graph axis scale changed the relative distance with respect to the options of a given attribute and thus changed the salience of the information in graphical representations. Experiment 1 showed that the differences in the graphical representations had a significant impact on the evaluation. Experiment 2 repeated the scale manipulation effect in a different scenario and extended it to a multi-options context. Experiment 3 disentangled the effect of scale distance manipulation from the other variables (e.g., scale resolution and assignment of attributes to axes) and further supported the finding of Experiment 1. These results indicated that attribute salience in graphical representations clearly affects evaluations and that graphs can be manipulated to cause very different impressions of the same data. This finding is not consistent with the axioms of normative economic theory. Experiment 3 also tested the attribute importance hypothesis, but the evidence indicated that the participants did not regard the longer axis as the more important attribute. Finally, we related our findings to the impact of visual processing on decision making and discussed them from the perspective of two-system cognitive theory.

Article
In the current paper we investigate how feedback over decision outcomes may affect future decisions. In an experimental study we demonstrate that if people receive feedback over the outcomes they obtained (factual outcomes'') and the outcomes they would have obtained had they decided differently (counterfactual outcomes''), they become regret-averse in subsequent decisions. This effect is not only observed when this feedback evoked regret (with counterfactual outcomes being higher than factual outcomes), but even when the feedback evoked no regret (with factual outcomes being equal to counterfactual outcomes). The findings suggest that this effect on subsequent decisions is at least partly due to the transfer of a comparison mind-set triggered in the prior choice.

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Three experiments investigated the relations between buyers' wealth or ability to pay (ATP) and sellers' first offers. Study 1 demonstrated a positive correlation between sellers' first offers and their perceptions of the buyer's ATP as well as its real economic power (indicated by the company's market value). In Study 2, sellers in a field experiment made higher offers to potential buyers of higher ATP. Study 3 examined the relations between buyer's ATP, the perception of its ability to obtain alternatives to a specific deal, and sellers' first offers. We found a positive correlation between sellers' perception of buyers' ATP, real ATP (as indicated by market value), and sellers' perception of buyers' availability of alternatives. As in Study 1, here too, the unit of analysis was the behavior of the individual participant. However, when sellers were primed to concentrate on buyers' alternatives, their first offers were negatively related to perceived buyer's alternatives.

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We examined choice behavior in younger versus older adults using a medical decision-making task similar to Medicare Part D. The study was designed to assess age differences in choice processes in general and specifically designed to examine the effect of choice set size on performance. Data are drawn from a larger study on choice and aging, in which ninety-six younger adults (ages 18--64) and 96 older adults (ages 65--91) selected a prescription drug plan from either 6 or 24 different options. As hypothesized, choice set size was a significant predictor of individuals' ability to choose the best plan. Participants who were presented with 24 plans were less likely to choose the correct prescription drug plan. Age did not have a negative effect on decision performance; however numeracy and speed of processing significantly affected performance across groups. Older adults were more likely to be characterized as satisficers on a decision personality measure, but this categorization did not predict performance on the choice task.

Article
A wise decider D uses the contents of his mind fully, accurately and efficiently. D's ideal decisions, i.e., those that best serve his interests, would be embedded in a comprehensive set of totally coherent judgments lodged in his mind. They would conform to the norms of statistical decision theory, which extracts quantitative judgments of fact and value from D's mind contents and checks them for coherence. However, the most practical way for D to approximate his ideal may not be with models that embody those norms, i.e., with applied decision theory (ADT). In practice, ADT can represent only some of D's judgments and those imperfectly. Quite different decision aid, including intuition, pattern recognition and cognitive vigilance (especially combined), typically outperform feasible ADT models---with some notable exceptions. However, decision theory training benefits D's informal decisions. ADT, both formal and informal, should become increasingly useful and widespread, as technical, cultural and institutional impediments are overcome.

Article
Research endeavors to determine the effectiveness of patient decision aids (PtDAs) have yielded mixed results. The conflicting evaluations are largely due to the different metrics used to assess the validity of judgments made using PtDAs. The different approaches can be characterized by Hammond's (1996) two frameworks for evaluating judgments: correspondence and coherence. This paper reviews the literature on the effectiveness of PtDAs and recasts this argument as a renewed debate between these two meta-theories of judgment. Evaluation by correspondence criteria involves measuring the impact of patient decision aids on metrics for which there are objective, external, and empirically justifiable values. Evaluation on coherence criteria involves assessing the degree to which decisions follow the logical implications of internal, possibly subjective, value systems/preferences. Coherence can exist absent of correspondence and vice versa. Therefore, many of the seemingly conflicting results regarding the effectiveness of PtDAs can be reconciled by considering that the two meta-theories contribute unique perspectives. We argue that one approach cannot substitute for the other, and researchers should not deny the value of either approach. Furthermore, we suggest that future research evaluating PtDAs include both correspondence and coherence criteria.

Article
Although the priority heuristic (PH) is conceived as a cognitive-process model, some of its critical process assumptions remain to be tested. The PH makes very strong ordinal and quantitative assumptions about the strictly sequential, non-compensatory use of three cues in choices between lotteries: (1) the difference between worst outcomes, (2) the difference in worst-case probabilities, and (3) the best outcome that can be obtained. These aspects were manipulated orthogonally in the present experiment. No support was found for the PH. Although the main effect of the primary worst-outcome manipulation was significant, it came along with other effects that the PH excludes. A strong effect of the secondary manipulation of worst-outcome probabilities was not confined to small differences in worst-outcomes; it was actually stronger for large worst-outcome differences. Overall winning probabilities that the PH ignores exerted a systematic influence. The overall rate of choices correctly predicted by the PH was close to chance, although high inter-judge agreement reflected systematic responding. These findings raise fundamental questions about the theoretical status of heuristics as fixed modules.

Article
The Allais Paradox, or common consequence effect, has been a standard challenge to normative theories of risky choice since its proposal over 60 years ago. However, neither its causes nor the conditions necessary to create the effect are well understood. Two experiments test the effects of losses and event splitting on the Allais Paradox. Experiment 1 found that the Allais Paradox occurs for both gain and mixed gambles and is reflected for loss gambles produced by reflection across the origin. Experiment 2 found that the Allais Paradox is eliminated by splitting the outcomes even when the probabilities used do not increase the salience of the common consequence. The results of Experiment 1 are consistent with Cumulative Prospect Theory, the current leading theory of risky choice. However, the results of Experiment 2 are problematic for Cumulative Prospect Theory and suggest that alternate explanations for the Allais Paradox must be sought.

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Economic games involving allocation of resources have been a useful tool for the study of decision making for both psychologists and economists. In two experiments involving a repeated-trials game over twenty opportunities, undergraduates made choices to distribute resources between themselves and an unseen, passive other either optimally (for themselves) but non-competitively, equally but non-optimally, or least optimally but competitively. Surprisingly, whether participants were told that the anonymous other was another student or a computer did not matter. Using such terms as game'' and player'' in the course of the session was associated with an increased frequency of competitive interaction was found in the first experiment. In agreement with prior research, participants whose resources were backed by monetary incentive acted the most optimally. Overall, equality was the modal strategy employed, although it is clear that motivational context affects the allocation of resources.

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Unbiased lotteries seem the least unfair and simplest procedures to allocate scarce indivisible resources to those with equal claims. But, when lotteries are repeated, it is not immediately obvious whether prior winners should be included or excluded. As in design questions surrounding single-shot lotteries, considerations of self-interest and distributive social preferences may interact. We investigate preferences for allowing participation of earlier winners in sequential lotteries. We found a strong preference for exclusion, both in settings where subjects were involved, and those where they were not. Subjects who answered questions about both settings did not differ in their tendency to prefer exclusion. Stated rationales significantly predicted choice but did not predict switching of choices between the two settings.

Article
Binary sequences are characterized by various features. Two of these characteristics---alternation rate and run length---have repeatedly been shown to influence judgments of randomness. The two characteristics, however, have usually been investigated separately, without controlling for the other feature. Because the two features are correlated but not identical, it seems critical to analyze their unique impact, as well as their interaction, so as to understand more clearly what influences judgments of randomness. To this end, two experiments on the perception of binary sequences orthogonally manipulated alternation rate and maximum run length (i.e., length of the longest run within the sequence). Results show that alternation rate consistently exerts a unique effect on judgments of randomness, but that the effect of alternation rate is contingent on the length of the longest run within the sequence. The effect of maximum run length was found to be small and less consistent. Together, these findings extend prior randomness research by integrating literature from the realms of perception, categorization, and prediction, as well as by showing the unique and joint effects of alternation rate and maximum run length on judgments of randomness.

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• University of Michigan
• Rotterdam School of Management
• New York University
• Princeton University
• University of Oregon