We examine how almost winning in roulette affects subsequent betting behavior. Our main finding is heterogeneity in gambler behavior with some gamblers less likely to bet on numbers that were near misses on the prior spin and other gamblers more likely to bet on near miss numbers. Using a unique data set from the game rapid roulette, we model the likelihood of a gambler betting on a near miss number while controlling for the favorite number bias and the likelihood of a number being a near miss. We also find no evidence that near misses in roulette leads to gamblers extending the time spent gambling or to the placing of more bets.

The article shows that when people consider differentiated goods or services that differ in price and quality, they exhibit a decision-making bias of “relative thinking”: relative price differences affect them even when economic theory suggests that only absolute price differences matter. This result is obtained in four different consumption categories. Sometimes subjects are affected only by relative price differences (“full relative thinking”) and sometimes also by absolute price differences (“partial relative thinking”). This behavior has implications for various disciplines, and it is particularly relevant in models dealing with horizontal or vertical differentiation, optimal pricing, competitive strategy, or advertising.

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.

In this introduction to the special issue on methodology, we provide background on its original motivation and a systematic overview of the contributions. The latter are discussed with correspondence to the phase of the scientific process they (most strongly) refer to: Theory construction, design, data analysis, and cumulative development of scientific knowledge. Several contributions propose novel measurement techniques and paradigms that will allow for new insights and can thus avail researchers in JDM and beyond. Another set of contributions centers around how models can best be tested and/or compared. Especially when viewed in combination, the papers on this topic spell out vital necessities for model comparisons and provide approaches that solve noteworthy problems prior work has been faced with.

We examine two departures of individual perceptions of randomness fromprobability theory: the hot hand and the gambler's fallacy, and theirrespective opposites. This paper's first contribution is to use data fromthe field (individuals playing roulette in a casino) to demonstrate theexistence and impact of these biases that have been previously documented in thelab. Decisions in the field are consistent with biased beliefs, although weobserve significant individual heterogeneity in the population. A secondcontribution is to separately identify these biases within a given individual,then to examine their within-person correlation. We find a positive andsignificant correlation across individuals between hot hand and gambler'sfallacy biases, suggesting a common (root) cause of the two related errors. Wespeculate as to the source of this correlation (locus of control), and suggestfuture research which could test this speculation.

How many judgment and decision making (JDM) researchers have not claimed to be building on Herbert Simon’s work? We identify two of Simon’s goals for JDM research: He sought to understand people’s decision processes—the descriptive goal—and studied whether the same processes lead to good decisions—the prescriptive goal. To investigate how recent JDM research relates to these goals, we analyzed the articles published in the Journal of Behavioral Decision Making and in Judgment and Decision Making from 2006 to 2010. Out of 377 articles, 91 cite Simon or we judged them as directly relating to his goals. We asked whether these articles are integrative, in the following sense: For a descriptive article we asked if it contributes to building a theory that reconciles different conceptualizations of cognition such as neural networks and heuristics. For a prescriptive article we asked if it contributes to building a method that combines ideas of other methods such as heuristics and optimization models. Based on our subjective judgments we found that the proportion of integrative articles was 67% of the prescriptive and 52% of the descriptive articles. We offer suggestions for achieving more integration of JDM theories. The article concludes with the thesis that although JDM researchers work under Simon’s spell, no one really knows what that spell is.

The endowment effect is a well-documented decision phenomenon, referring to a tendency that people price a commodity higher when selling it than when buying it. This phenomenon can be interpreted as a sort of inertia, an unwillingness to make a change, or in other words an attachment to the status-quo. People with autism dislike social interaction, and are thus probably less willing to buy and sell items and more attached to the status quo. Previous research revealed that T-carriers of a single-nucleotide polymorphism (SNP) of the dopamine beta-hydroxylase (DBH) gene, rs1611115 (C-1021T), are associated with autism and difficulty in social interaction. Therefore, rs1611115 may modulate the endowment effect. In the current study, the subjects sold and bought lotteries with various probabilities of winning money and provided saliva for genotyping. We found that T-carriers (people of CT genotype in this study) exhibited greater endowment effects compared to people of CC genotype. We discuss another two possible explanations of our results: empathy and loss aversion. This is the first attempt to research the endowment effect from the perspective of genes. The result indicates that an SNP of genes (an innate factor) can exert an observable effect on human market activities.

Following up on a recent debate, we examined advice taking in dyads compared to individuals in a set of three studies (total N = 303 dyads and 194 individuals). Our first aim was to test the replicability of an important previous finding, namely that dyads heed advice less than individuals because they feel more confident in the accuracy of their initial judgments. Second, we aimed to explain dyads’ behavior based on three premises: first, that dyads understand that the added value of an outside opinion diminishes when the initial pre-advice judgment is made by two judges rather than one judge (given that the dyad members’ opinions are independent of each other); second, that they fail to recognize when the assumption of independence of opinions does not hold; and third, that the resistance to advice commonly observed in individuals persists in groups but is neither aggravated nor ameliorated by the group context. The results of our studies show consistently that previous findings on advice taking in dyads are replicable. They also support our hypothesis that groups exhibit a general tendency to heed advice less than individuals, irrespective of whether the accuracy of their initial judgments warrants this behavior. Finally, based on the three assumptions mentioned above, we were able to make accurate predictions about advice taking in dyads, prompting us to postulate a general model of advice taking in groups of arbitrary size.

Overprecision is the most robust type of overconfidence. We present a new method that significantly reduces this bias and offers insight into its underlying cause. In three experiments, overprecision was significantly reduced by forcing participants to consider all possible outcomes of an event. Each participant was presented with the entire range of possible outcomes divided into intervals, and estimated each interval’s likelihood of including the true answer. The superiority of this Subjective Probability Interval Estimate (SPIES) method is robust to range widths and interval grain sizes. Its carryover effects are observed even in subsequent estimates made using the conventional, 90% confidence interval method: judges who first made SPIES judgments considered a broader range of values in subsequent conventional interval estimates as well.

Hammond (1996) argued that much of the research in the field of judgment and decision making (JDM) can be categorized as focused on either coherence or correspondence (C&C) and that, in order to understand the findings of the field, one needs to understand the differences between these two criteria. Hammond’s claim is that conclusions about the competence of judgments and decisions will depend upon the selection of coherence or correspondence as the criterion (Hammond, 2008). First, I provide an overview of the terms coherence and correspondence (C&C) as philosophical theories of truth and relate them to the field of JDM. Second, I provide an example of Hammond’s claim by examining literature on base rate neglect. Third, I examine Hammond’s claim as it applies to the broader field of JDM. Fourth, I critique Hammond’s claim and suggest that refinements to the C&C distinction are needed. Specifically, the C&C distinction 1) is more accurately applied to criteria than to researchers, 2) should be refined to include two important types of coherence (inter and intrapersonal coherence) and 3) neglects the third philosophical theory of truth, pragmatism. Pragmatism, as a class of criteria in JDM, is defined as goal attainment. In order to provide the most complete assessment of human judgment possible, and understand different findings in the field of JDM, all three criteria should be considered.