This article presents a theory of reasoning about moral propositions that is based on four fundamental principles. First, no simple criterion picks out propositions about morality from within the larger set of deontic propositions concerning what is permissible and impermissible in social relations, the law, games, and manners. Second, the mechanisms underlying emotions and deontic evaluations are independent and operate in parallel, and so some scenarios elicit emotions prior to moral evaluations, some elicit moral evaluations prior to emotions, and some elicit them at the same time. Third, deontic evaluations depend on inferences, either unconscious intuitions or conscious reasoning. Fourth, human beliefs about what is, and isn’t, moral are neither complete nor consistent. The article marshals the evidence, which includes new studies, corroborating these principles, and discusses the relations between them and other current theories of moral reasoning.

Five experiments addressed a controversy in the probability judgment literature that centers on the efficacy of framing probabilities as frequencies. The natural frequency view predicts that frequency formats attenuate errors, while the nested-sets view predicts that highlighting the set-subset structure of the problem reduces error, regardless of problem format. This study tested these predictions using a conjunction task. Previous studies reporting that frequency formats reduced conjunction errors confounded reference class with problem format. After controlling this confound, the present study’s findings show that conjunction errors can be reduced using either a probability or a frequency format, that frequency effects depend upon the presence of a reference class, and that frequency formats do not promote better statistical reasoning than probability formats.

Theoretical equivalence exists among various auction mechanisms, specifically the Second-Price-Auction (SPA), a competitive environment, and the BDM mechanism, a non-competitive environment. Yet, empirical studies suggest that behavior in these mechanisms may diverge. Our experimental study examines the WTP and the WTA of individuals by analyzing buying and selling bidding patterns both for a physical product (mugs) and for two types of lotteries (regular lotteries and extreme lotteries) in these two auctions mechanism: SPA and BDM. We found that the WTP in the SPA is higher than the WTP in the BDM for mugs and for regular lotteries, while the mechanisms do not differ significantly for extreme lotteries. In addition, the WTA in the SPA is lower than in the BDM for regular lotteries only. These results indicate that the WTP and WTA, as well as the WTA-WTP gap, tend to differ in the SPA and in the BDM as a result of the interaction between the competitiveness effect and other psychological effects on bidding patterns for riskless and risky assets. In addition, the current study suggests that the competitiveness effect depends not only on the type of mechanism (SPA), but also on the type of item (physical assets or lotteries) and the type of lottery. In addition, the influence of the competitiveness effect may vary between buying and selling positions.

This study employs a Discrete Choice Experiment (DCE) in the health-care sector to test the loss aversion theory that is derived from reference-dependent preferences: The absolute subjective value of a deviation from a reference point is generally greater when the deviation represents a loss than when the same-sized change is perceived as a gain. As far as is known, this paper is the first to use a DCE to test the loss aversion theory. A DCE is a highly suitable tool for such testing because it estimates the marginal valuations of attributes, based on deviations from a reference point (a constant scenario). Moreover, loss aversion can be examined for each attribute separately. Another advantage of a DCE is that is can be applied to non-traded goods with non-tangible attributes. A health-care event is used for empirical illustration: The loss aversion theory is tested within the context of preference structures for maternity-ward attributes, estimated using data gathered from 3850 observations made by a sample of 542 women who had recently given birth. Seven hypotheses are presented and tested. Overall, significant support for behavioral loss aversion theories was found.

In preventative health decisions, such as the decision to undergo an invasive screening test or treatment, people may be deterred from selecting the test because its perceived disutility relative to not testing is greater than the utility associated with prevention of possible disease. The prospect theory editing operation, by which a decision maker’s reference point is determined, can have important effects on the disutility of the test. On the basis of the prospect theory value function, this paper develops two approaches to reducing disutility by directing the decision maker’s attention to either (actual) past or (expected) future losses that result in shifted reference points. After providing a graphical description of the approaches and a mathematical proof of the direction of their effect on judgment, we briefly illustrate the potential value of these approaches with examples from qualitative research on prostate cancer treatment decisions.

Subjects performed a decision task (Grether, 1980) in both a well-rested and experimentally sleep-deprived state. We found two main results: 1) final choice accuracy was unaffected by sleep deprivation, and yet 2) the estimated decision model differed significantly following sleep-deprivation. Following sleep deprivation, subjects placed significantly less weight on new information in forming their beliefs. Because the altered decision process still maintains decision accuracy, it may suggest that increased accident and error rates attributed to reduced sleep in modern society stem from reduced auxiliary function performance (e.g., slowed reaction time, reduced motor skills) or other components of decision making, rather than the inability to integrate multiple pieces of information.

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.