Most speakers experience unclarity about the application of predicates like tall and red to liminal cases. We formulate alternative psychological hypotheses about the nature of this unclarity, and report experiments that provide a partial test of them. A psychologized version of the ‘vagueness-as-ignorance’ theory is then advanced and defended.

Because the conjunction pandq implies p, the value of a bet on pandq cannot exceed the value of a bet on p at the same stakes. We tested recognition of this principle in a betting paradigm that (a) discouraged misreading p as pandnotq, and (b) encouraged genuinely conjunctive reading of pandq. Frequent violations were nonetheless observed. The findings appear to discredit the idea that most people spontaneously integrate the logic of conjunction into their assessments of chance.

Although the role of emotion in socioeconomic decision making is increasingly recognised, the impact of specific emotional disorders, such as anxiety disorders, on these decisions has been surprisingly neglected. Twenty anxious patients and twenty matched controls completed a commonly used socioeconomic task (the Ultimatum Game), in which they had to accept or reject monetary offers from other players. Anxious patients accepted significantly more unfair offers than controls. We discuss the implications of these findings in light of recent models of anxiety, (...) in particular the importance of interpersonal factors and assertiveness in an integrated model of decision making. Finally, we were able to show that pharmacological serotonin used to treat anxious symptomatology tended to normalise decision making, further confirming and extending the role of serotonin in co-operation, prosocial behaviour, and social decision making. These results show, for the first time, a different pattern of socioeconomic behaviour in anxiety disordered patients, in addition to the known memory, attentional and emotional biases that are part of this pathological condition. (shrink)

Efforts to contain the spread of the coronavirus emphasize the central role of citizens’ compliance with self-protective behaviors. Understanding the processes underlying the decision to self-protect is, therefore, essential for effective risk communication during the COVID-19 pandemic. In the present study, we investigate the determinants of perceived threat and engagement in self-protective measures in the United Kingdom, Italy, and Austria during the first wave of the pandemic. The type of disease and the type of numerical information regarding the disease were (...) manipulated. Participants’ cognitive and emotional risk assessment as well as self-reported engagement in protective behaviors were measured. Results show that worry was the best predictor of perceived threat in all countries. Moreover, a path analysis revealed that worry and perceived threat serially mediated the effect of type of disease on engagement in self-protective behaviors. The numerical framing manipulation did not significantly impact behavior but had a direct effect on worry and an indirect effect on perceived threat. These results are in line with theoretical accounts that identify emotions as a central determinant for risk perception. Moreover, our findings also suggest that effective risk communication during the COVID-19 pandemic should not stress comparisons to other, well-known viral diseases, as this can ultimately reduce self-protective behaviors. (shrink)

We propose a theory that relates perceived evidence to numerical probability judgment. The most successful prior account of this relation is Support Theory, advanced in Tversky and Koehler. Support Theory, however, implies additive probability estimates for binary partitions. In contrast, superadditivity has been documented in Macchi, Osherson, and Krantz, and both sub- and superadditivity appear in the experiments reported here. Nonadditivity suggests asymmetry in the processing of focal and nonfocal hypotheses, even within binary partitions. We extend Support Theory by revising (...) its basic equation to allow such asymmetry, and compare the two equations’ ability to predict numerical assessments of probability from scaled estimates of evidence for and against a given proposition. Both between- and within-subject experimental designs are employed for this purpose. We find that the revised equation is more accurate than the original Support Theory equation. The implications of asymmetric processing on qualitative assessments of chance are also briefly discussed. (shrink)

ABSTRACTWe examined whether enhancing the emotionality of a referent public good influences the subsequent valuation of a target public good. We predicted that it would and that the directionality of its impact would depend on a fundamental cognitive process – categorisation. If the target and referent goods belong to the same domain, we expected that the effect on the target would be in the same direction as the emotional enhancement of the referent. However, if the target and referent goods belong (...) to different domains, we expected that the effect on the target would be either negligible or in the opposite direction to that of the emotional enhancement of the referent. In Experiment 1 we examined the impact of emotionally enhancing a referent public good on feelings towards a target public good, whereas in Experiment 2 on the willingness to contribute towards a target public good. The results support the predicted interaction, which was... (shrink)

It is easy to construct pairs of sentences X, Y that lead many people to ascribe higher probability to the conjunction X‐and‐Y than to the conjuncts X, Y. Whether an error is thereby committed depends on reasoners' interpretation of the expressions “probability” and “and.” We report two experiments designed to clarify the normative status of typical responses to conjunction problems.

A way to make people save energy is by informing them that “comparable others” save more. We investigated whether one can further improve this nudge by manipulating Who the “comparable others” are. We asked participants to imagine receiving feedback stating that their energy consumption exceeded that of “comparable others” by 10%. We varied Who the “comparable others” were in a 2 × 2 design: they were a household that was located either in the same neighborhood as themselves or in a (...) different neighborhood, and its members were either identified (by names and a photograph) or unidentified. We also included two control conditions: one where no feedback was provided, and one where only statistical feedback was provided (feedback about an average household). We found that it matters Who the “comparable others” are. The most effective feedback was when the referent household was from the same neighborhood as the individual’s and its members were not identified. (shrink)

The European market has faced a series of recurrent food scares, e.g. mad cow disease, chicken flu, dioxin poisoning in chickens, salmons and recently also in pigs (Italian newspaper Corriere della Sera , 07/12/2008). These food scares have had, in the short term, major socio-economic consequences, eroding consumer confidence and decreasing the willingness to buy potentially risky food products. The research reported in this paper considered the role of commitment to a food product in the context of food scares, and (...) in particular the effect of commitment on the purchasing intentions of consumers, on their attitude towards the product, and on their trust in the food supply chain. After the initial commitment had been obtained, a threat scenario evoking a risk associated with a specific food was presented, and a wider, related request was then made. Finally, a questionnaire tested the effects of commitment on the participants’ attitude towards the product. The results showed that previous commitment can increase consumers’ behavioural intention to purchase and their attitude towards the food product, even in the presence of a potential hazard. (shrink)