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.

According to regulatory fit theory (Higgins, 2000), when people make decisions with strategies that sustain their regulatory focus orientation, they “feel right” about what they are doing, and this “feeling-right” experience then transfers to subsequent choices, decisions, and evaluations. The present research was designed to link the concept of regulatory fit to functional accounts of counterfactual thinking. In the present study, participants generated counterfactuals about their anagram performance, after which persistence on a second set of anagrams was measured. Under promotion framing (i.e., find 90% or more of all the possible words) upward counterfactual thinking in general elicited larger increases in persistence than did downward counterfactual thinking in general, but under prevention framing (i.e., avoid failing to find 90% or more of all the possible words) upward evaluation (comparing reality to a better reality) elicited larger increases in persistence than did upward reflection (focusing on a better reality), whereas downward reflection (focusing on a worse reality) elicited larger increases in persistence than did downward evaluation (comparing reality to a worse reality). In all, the present findings suggest that the generation of counterfactuals enhances the likelihood that individuals will engage in courses of action that fit with their regulatory focus orientation.

In this article, I will show how several observed biases in human probabilistic reasoning can be partially explained as good heuristics for making inferences in an environment where probabilities have uncertainties associated to them. Previous results show that the weight functions and the observed violations of coalescing and stochastic dominance can be understood from a Bayesian point of view. We will review those results and see that Bayesian methods should also be used as part of the explanation behind other known biases. That means that, although the observed errors are still errors under the laboratory conditions in which they are demonstrated, they can be understood as adaptations to the solution of real life problems. Heuristics that allow fast evaluations and mimic a Bayesian inference would be an evolutionary advantage, since they would give us an efficient way of making decisions.

This paper tests whether logically equivalent risk formats can lead to different health state utilities elicited by means of the traditional standard gamble (SG) method and a modified version of the method that we call “double lottery.” We compare utilities for health states elicited when probabilities are framed in terms of frequencies with respect to 100 people in the population (i.e., X out of 100 who follow a medical treatment will die) with SG utilities elicited for frequencies with respect to 1,000 people in the population (i.e., Y out of 1,000 who follow a medical treatment will die). We found that people accepted a lower risk of death when success and failure probabilities were framed as frequencies type “Y deaths out of 1,000” rather than as frequencies type “X deaths out of 100” and hence the utilities for health outcomes were higher when the denominator was 1000 than when it was 100. This framing effect, known as Ratio Bias, may have important consequences in resource allocation decisions.

People are often more likely to accept risky monetary gambles with positive expected values when the gambles will be played more than once. We investigated whether this distinction between single-play and multiple-play gambles extends to medical treatments for individual patients and groups of patients. Resident physicians and medical students (n = 69) and undergraduates (n = 99) ranked 9 different flu shots and a no-flu-shot option in 1 of 4 combinations of perspective (individual patient vs. group of 1000 patients) and uncertainty frame (probability vs. frequency). The rank of the no-flu-shot option (a measure of preference for treatment vs. no treatment) was not significantly related to perspective or participant population. The main effect of uncertainty frame and the interaction between perspective and uncertainty frame approached significance (0.1 > p > 0.05), with the no-flu-shot option faring particularly poorly (treatment faring particularly well) when decisions about many patients were based on frequency information. Undergraduate participants believed that the no-flu-shot option would be less attractive (treatment would be more attractive) in decisions about many patients, but these intuitions were inconsistent with the actual ranks. These results and those of other studies suggest that medical treatments for individuals and groups are not analogous to single-play and multiple-play monetary gambles, perhaps because many people are unwilling to aggregate treatment outcomes over patients in the same way that they would compute net gains or losses over monetary gambles.

When survey respondents rate the quality of life (QoL) associated with a health condition, they must not only evaluate the health condition itself, but must also interpret the meaning of the rating scale in order to assign a specific value. The way that respondents approach this task depends on subjective interpretations, resulting in inconsistent results across populations and tasks. In particular, patients and non-patients often give very different ratings to health conditions, a discrepancy that raises questions about the objectivity of either groups’ evaluations. In this study, we found that the perspective of the raters (i.e., their own current health relative to the health conditions they rated) influences the way they distinguish between different health states that vary in severity. Consistent with prospect theory, a mild and a severe lung disease scenario were rated quite differently by lung disease patients whose own health falls between the two scenarios, whereas healthy non-patients, whose own health was better than both scenarios, rated the two scenarios as much more similar. In addition, we found that the context of the rating task influences the way participants distinguish between mild and severe scenarios. Both patients and non-patients gave less distinct ratings to the two scenarios when each were presented in isolation than when they were presented alongside other scenarios that provided contextual information about the possible range of severity for lung disease. These results raise continuing concerns about the reliability and validity of subjective QoL ratings, as these ratings are highly sensitive to differences between respondent groups and the particulars of the rating task.

Some studies have found that choices become more risk averse after gains and more risk seeking after losses, although other studies have found the opposite. The latter tend to use hypothetical cases that encourage deliberation. In the current study, we examined the effects of prior gains and losses on a task designed to encourage less reflective decision making, the Iowa Gambling Task (IGT). Fifty participants conducted a manipulated decision-making task in which one group gained money, whereas the other group lost money, followed by the IGT. Participants who experienced a prior monetary loss displayed more risky choice behavior on the IGT than subjects who experienced a prior gain. These effects were not mediated by a positive or negative affect, although the sample size may have been too small to detect a small effect.

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).

An experienced decision aider reflects on how misaligned priorities produce decision research that is less useful than it could be. Scientific interest and professional standing may motivate researchers — and their funders and publishers — more powerfully than concern to help people make better

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.