Likelihood Judgments Research Articles

Wishful Thinking about the Future: Does Desire Impact Optimism?

AbstractThe notion that desire for an outcome inflates optimism about that outcome has been dubbed the desirability bias or wishful thinking. In this paper, we discuss the importance of distinguishing wishful thinking from the more general concept of motivated reasoning, and we explain why documenting overoptimism or correlations between preferences and optimism is not sufficient to infer a desirability bias. Then, we discuss results from a review and meta‐analysis of the experimental literature on wishful thinking. These findings, in conjunction with more recent work, not only highlight important moderators and mediators of the desirability bias but also point out limitations of the empirical research on the bias. These results also reveal an important difference between how likelihood judgments and discrete outcome predictions respond to desirability of outcomes. We conclude by presenting avenues for future research useful for understanding wishful thinking's manifestation in everyday environments and its integration with related phenomena.

Automatic optimism: The affective basis of judgments about the likelihood of future events.

People generally judge that the future will be consistent with their desires, but the reason for this desirability bias is unclear. This investigation examined whether affective reactions associated with future events are the mechanism through which desires influence likelihood judgments. In 4 studies, affective reactions were manipulated for initially neutral events. Compared with a neutral condition, events associated with positive reactions were judged as likely to occur, and events associated with negative reactions were judged as unlikely to occur. Desirability biases were reduced when participants could misattribute affective reactions to a source other than future events, and the relationship between affective reactions and judgments was influenced when approach and avoidance motivations were independently manipulated. Together, these findings demonstrate that positive and negative affective reactions to potential events cause the desirability bias in likelihood judgments and suggest that this effect occurs because of a tendency to approach positive possibilities and avoid negative possibilities.

Identity maintenance and cognitive test performance

Identity maintenance processes can affect performance when that performance is relevant to an important self-identity, including performance on standardized tests of mental ability. Affect control theory proposes that individuals’ performances are motivated to maintain concordance between fundamental sentiments about identities and contextually driven transient meanings. An experimental test used the college major identity and randomly assigned participants to different instruction sets that made an aptitude test either relevant to their major or a contrasting major (All participants took the Raven advanced progressive matrices test.). Participants who took a test of mental ability that they expected would verify their identity scored two and a half points higher than did participants who took a test of mental ability expected to verify a contrasting identity. Results strongly support the fundamental validity of affect control theory’s predictions about situational meaning maintenance [Heise, David R., 1979. Understanding Events: Affect and the Construction of Social Action. Cambridge University Press, New York; Heise, David R., 1985. Affect control theory: respecification, estimation and tests of the formal model. Journal of Mathematical Sociology 11, 191–222; Heise, David R., 2007. Expressive Order: Confirming Sentiments in Social Actions. Springer Science + Business Media, LLC, New York; Heise, David R., MacKinnon, Neil J., 1988. Affective bases of likelihood judgments. In: Smith-Lovin, Lynn, Heise, David R. (Eds.), Analyzing Social Interaction: Advances in Affect Control Theory. Gordon and Breach, New York, pp. 133–152].

Risk matrix input data biases

AbstractRisk matrices used in industry characterize particular risks in terms of the likelihood of occurreRisk matrix input data biaseshe actualized risk. Human cognitive bias research led by Daniel Kahneman and Amos Tversky exposed systematic translations of objective probability and value as judged by human subjects. Applying these translations to the risk matrix allows the formation of statistical hypotheses of risk point placement biases. Industry‐generated risk matrix data reveals evidence of biases in the judgment of likelihood and consequence—principally, likelihood centering, a systematic increase in consequence, and a diagonal bias. Statistical analyses are conducted with linear regression, normal distribution fitting, and Bayesian analysis. Evidence presented could improve risk matrix based risk analysis prevalent in industry. © 2008 Wiley Periodicals, Inc. Syst Eng

KR17 Risk Cube Data Biases

AbstractRisk cubes used in industry characterize particular risks in terms of the likelihood of occurrence, and the consequence of the actualized risk. Human cognitive bias research led by Daniel Kahneman and Amos Tversky exposed systematic translations of objective probability and value as judged by human subjects. An examination of industry‐generated risk cube data reveals evidence of biases in the judgment of likelihood and consequence. In addition, other biases – including a ‘diagonal bias’ – are revealed in the risk cube data. The evidence presented could improve risk cube based risk analysis.

Are people excessive or judicious in their egocentrism? A modeling approach to understanding bias and accuracy in people's optimism.

People are often egocentric when judging their likelihood of success in competitions, leading to overoptimism about winning when circumstances are generally easy and to overpessimism when the circumstances are difficult. Yet, egocentrism might be grounded in a rational tendency to favor highly reliable information (about the self) more so than less reliable information (about others). A general theory of probability called extended support theory was used to conceptualize and assess the role of egocentrism and its consequences for the accuracy of people's optimism in 3 competitions (Studies 1-3, respectively). Also, instructions were manipulated to test whether people who were urged to avoid egocentrism would show improved or worsened accuracy in their likelihood judgments. Egocentrism was found to have a potentially helpful effect on one form of accuracy, but people generally showed too much egocentrism. Debias instructions improved one form of accuracy but had no impact on another. The advantages of using the EST framework for studying optimism and other types of judgments (e.g., comparative ability judgments) are discussed.

Disaster preparedness and perception of flood risk: A study in an alpine valley in Italy

Italy is a country highly vulnerable to floods and landslides. The present study aims to investigate disaster preparedness and perception of flood risk in a group of people living in an alpine valley in the north of Italy. Four hundred seven adult residents in nine communities exposed to hydrogeological risk were interviewed by using a structured questionnaire. Participants were asked about the adoption of a set of protective behaviors that can prevent negative consequences of floods. Perception of flood risk was assessed by means of a one-dimensional scale that was developed and validated by the authors. Items included in this scale asked participants to estimate likelihood of occurrence of different flood consequences and to express feelings of worry associated to them. Socio-demographic and experiential information on respondents were also collected. Overall, results showed that most of respondents were fairly well prepared to deal with a future flood disaster. Correlational and regression analyses indicated that disaster preparedness was positively associated with risk perception. In accordance with literature, there was not a significant relation between likelihood judgments and adoption of protective behaviors, while feelings of worry were associated with disaster preparedness. Authors interpret their results in relation to the socio-environmental characteristics of the studied communities. Theoretical, empirical and practical implications of the findings are also discussed.

Accountability and Affect in Auditor Judgment

This paper examines whether auditors' affect toward client management impacts an auditor's objective evaluation of evidence in fraud likelihood judgments. In addition to an overall judgment, this research also explores whether affect impacts all evidence evaluation equally or impacts only certain evidence evaluation in auditors' judgment processes. This research proposes client likeability will impact inexperienced auditors' evidence evaluation through errant attribution to specific evidence statements rather than uniformly through the evaluation process. Accountability and experience are included as potential moderators to the errant attribution. Results indicate that likeability, experience, and accountability interact impacting the overall fraud likelihood judgment. Specifically, inexperienced and non-accountable auditors erroneously include affect in their overall fraud likelihood judgments. For individual evidence assessments, client likeability impacts inexperienced auditors' assessments of specific statements, but not all client provided statements. However, client likeability does not impact experienced auditors individual statement assessments. The implication of these findings suggest that through experience and training, audit professionals gain the ability to identify and exclude irrelevant factors in professional judgment tasks.

Contrasting stochastic and support theory accounts of subadditivity

Numerous studies have found that likelihood judgment typically exhibits subadditivity in which judged probabilities of events are less than the sum of judged probabilities of constituent events. Whereas traditional accounts of subadditivity attribute this phenomenon to deterministic sources, this paper demonstrates both formally and empirically that subadditivity is systematically influenced by the stochastic variability of judged probabilities. First, making rather weak assumptions, we prove that regressive error (or variability) in mapping covert probability judgments to overt responses is sufficient to produce subadditive judgments. Experiments follow in which participants provided repeated probability estimates. The results support our model assumption that stochastic variability is regressive in probability estimation tasks and show the contribution of such variability to subadditivity. The theorems and the experiments focus on within-respondent variability, but most studies use between-respondent designs. Numerical simulations extend the work to contrast within- and between-respondent measures of subadditivity. Methodological implications of all the results are discussed, emphasizing the importance of taking stochastic variability into account when estimating the role of other factors (such as the availability bias) in producing subadditive judgments.

Another look at why people are reluctant to exchange lottery tickets.

People are reluctant to exchange lottery tickets, a result that previous investigators have attributed to anticipated regret. The authors suggest that people's subjective likelihood judgments also make them disinclined to switch. Four studies examined likelihood judgments with respect to exchanged and retained lottery tickets and found that (a) exchanged tickets are judged more likely to win a lottery than are retained tickets and (b) exchanged tickets are judged more likely to win the more aversive it would be if the ticket did win. The authors provide evidence that this effect occurs because the act of imagining an exchanged ticket winning the lottery increases the belief that such an event is likely to occur.

The impact of perceived experience on likelihood judgments for self and others: an experimental approach

AbstractThis study examines the effect of an experimental manipulation of perceived experience on self and others' likelihood ratings for a set of relatively commonplace misfortunes. Participants were randomly assigned to a condition in which they were asked whether they had ever experienced the events (designed to induce higher perceived experience) or whether they had done so frequently, typically, etc. (designed to induce lower perceived experience). The manipulation led to increases in ratings of both perceived self‐likelihood and others' likelihood, in ease of imagining the outcome and recall of a past occurrence, and to decreases in perceived control over the events in the higher perceived experience condition. The increases in ease of imagining mediated the impact of manipulated experience on comparative likelihood whereas the decreases in perceived control did not. There was little evidence that event controllability moderated the impact of experience on comparative likelihood for these events. Copyright © 2006 John Wiley & Sons, Ltd.

On decision making without likelihood judgment

Subjective expected utility, prospect theory and most other formal models of decision making under uncertainty are probabilistic: they assume that in making choices people judge the likelihood of relevant uncertainties. Clearly, in many situations people do indeed judge likelihood. However, we present studies suggesting that there are also many situations in which people do not judge likelihood and instead base their decisions on intuitively generated, non-probabilistic rules or rationales. Thus, we argue that real-world situations are of two types. In situations eliciting a probabilistic mindset, people rely on judgments of likelihood. In situations eliciting a non-probabilistic mindset, they neglect judgments of likelihood. We suggest three factors that may influence the tendency towards either probabilistic or non-probabilistic mindsets. We also outline how extant probabilistic theories may be complemented by non-probabilistic models.

A heuristics approach to understanding cancer risk perception: Contributions from judgment and decision-making research

The likelihood judgments that people make about their risks for cancer have important implications. At the individual level, risk estimates guide protective actions, such as cancer screening. However, at the extremes, exaggerated risk judgments can also lead to anxiety that degrades quality of life or to aggressive self-protective actions that are unwarranted given the objective risks. At the policy level, risk judgments may serve as an indicator of societal perceptions of the "war" against cancer. Using risk judgments, the public expresses its belief about whether we are winning. We present theoretical perspectives from judgment and decision making, illustrate how they can explain some of the existing empirical findings in the cancer risk literature, and describe additional predictions that have not yet been tested. Overall, we suggest that theories from the judgment and decision-making perspective offer a potentially powerful view for understanding and improving risk judgments for cancer and other diseases.

Contingent approaches to making likelihood judgments about polychotomous cases: the influence of task factors

AbstractTwo experiments tested the influence of three task factors on respondents' tendency to use normative, heuristic, and random approaches to making likelihood judgments about polychotomous cases (i.e., cases in which there is more than one alternative to a focal hypothesis). Participants estimated their likelihood of winning hypothetical raffles in which they and other players held various numbers of tickets. Responding on non‐numeric scales (vs. numeric ones) and responding under time pressure (vs. self‐paced) increased participants' use of a comparison‐heuristic approach, resulting in non‐normative judgment patterns. A manipulation of evidence representation (whether ticket quantities were represented by numbers or more graphically by bars) did not have reliably detectable effects on processing approaches to likelihood judgment. The authors discuss the implications of these findings for the further development of likelihood judgment theories, and they discuss parallels between contingent processing in choice and contingent processing in likelihood judgment. Copyright © 2005 John Wiley & Sons, Ltd.

Bayesian inference in disputed authorship: A case study of cognitive errors and a new system for decision support

Bayesian inference provides a formal framework for assessing the odds of hypotheses in light of evidence. This makes Bayesian inference applicable to a wide range of diagnostic challenges in the field of chance discovery, including the problem of disputed authorship that arises in electronic commerce, counter-terrorism and other forensic applications. For example, when two documents are so similar that one is likely to be a hoax written from the other, the question is: Which document is most likely the source and which document is most likely the hoax? Here I review a Bayesian study of disputed authorship performed by a biblical scholar, and I show that the scholar makes critical errors with respect to several issues, namely: Causal Basis, Likelihood Judgment and Conditional Dependency. The scholar’s errors are important because they have a large effect on his conclusions and because similar errors often occur when people, both experts and novices, are faced with the challenges of Bayesian inference. As a practical solution, I introduce a graphical system designed to help prevent the observed errors. I discuss how this decision support system applies more generally to any problem of Bayesian inference, and how it differs from the graphical models of Bayesian Networks.

Aging and Conditional Probability Judgments: A Global Matching Approach.

Age differences in bias in conditional probability judgments were investigated based on predictions derived from the Minerva-Decision Making model (M. R. P. Dougherty, C. F. Gettys, & E. E. Ogden, 1999), a global matching model of likelihood judgment. In this study, 248 younger and older adults completed frequency judgment and conditional probability judgment tasks. Age differences in the frequency judgment task are interpreted as an age-related deficit in memory encoding. Older adults' stronger biases in the probability judgment task point to age differences in criterion setting. Age-related biases were eliminated when age groups were equated on memory encoding by means of study time manipulation. The authors conclude that older adults' stronger judgment biases are a function of memory impairment.

Intuitive evaluation of likelihood judgment producers: evidence for a confidence heuristic

AbstractThis research tests the hypothesis of Yates et al. (1996) that people prefer judgment producers who make extreme confidence judgments. In each of three experiments, college students evaluated two fictional financial advisors who judged the likelihood that each of several stocks would increase in value. One of the advisors (the moderate advisor) was reasonably well calibrated and the other (the extreme advisor) was overconfident. In all three experiments, participants tended to prefer the extreme advisor. Experiments 2 and 3 showed that the advisors' confidence influenced participants' perception of their knowledge, and Experiment 3 showed that it influenced their perception of the number of categorically correct judgments they made. Both of these variables were, in turn, related to participants' preferences. Experiment 3 also suggested that need for cognition and right‐wing authoritarianism are positively related to preference for the extreme advisor. A quantitative model is presented, which captures the basic pattern of results. This model includes the assumption that people use a confidence heuristic; they assume that a more confident advisor makes more categorically correct judgments and is more knowledgeable. Copyright © 2004 John Wiley & Sons, Ltd.

The privileged status of prestigious terminology: impact of "medicalese" on clinical judgments.

Health professionals frequently use medical terminology like dyspnea or nasopharyngitis. These two studies examine how the use of medical terms affects the judgments of seriousness, prevalence, and disease; and diagnostic judgments. In study 1, a survey containing the names of 22 diseases with either a medical or lay description was completed by 47 undergraduate psychology students and 25 medical students, who were asked to judge seriousness, prevalence, and how "disease-like" it was. In study 2, undergraduate students learned four "pseudopsychiatry" conditions, each with four associated features. Features were presented in lay or medical versions. They were then tested with 18 new cases with two medical features from one condition and two lay terms from the other. In study 1, the medical students rated conditions as more disease-like, more serious, and less prevalent than did the psychology students. Medical descriptions were seen as significantly less common and somewhat more serious and more disease-like. In study 2, the participants rated the condition with medical features consistently more likely than the alternative, regardless of training condition. The specific words used to describe a feature or condition can have an impact on judgments of likelihood of disease, and, to a lesser extent, judgments of seriousness.

When mutations meet motivations: Attitude biases in counterfactual thought

The present research examines whether existing attitudes can spontaneously bias the content and direction of generated counterfactual thoughts, and whether these thoughts influence subsequent attitude-relevant judgments. Two experimental studies demonstrate that attitudes can bias the content of counterfactual thoughts, and that these biased thoughts in turn predict polarized attitudes. These effects were obtained regardless of whether explicit instructions for counterfactual generation were given. Furthermore, both studies demonstrate that these effects are mediated by judgments of future likelihood. Implications of these results for theories of counterfactual thinking and persuasion are discussed.

Partition priming in judgment under uncertainty.

We show that likelihood judgments are biased toward an ignorance-prior probability that assigns equal credence to each mutually exclusive event considered by the judge. The value of the ignorance prior depends crucially on how the set of possibilities (i.e., the state space) is subjectively partitioned by the judge. For instance, asking "what is the probability that Sunday will be hotter than any other day next week?" facilitates a two-fold case partition, [Sunday hotter, Sunday not hotter], thus priming an ignorance prior of 1/2. In contrast, asking "what is the probability that the hottest day of the week will be Sunday?" facilitates a seven-fold class partition, [Sunday hottest, Monday hottest, etc.], priming an ignorance prior of 1/7. In four studies, we observed systematic partition dependence: Judgments made by participants presented with either case or class formulations of the same query were biased toward the corresponding ignorance prior.