Recently it has been observed that different choices can be made about structurally identical risky decisions depending on whether information about outcomes and their probabilities is learned by description or from experience. Current evidence is equivocal with respect to whether this choice “gap” is entirely an artefact of biased samples. The current experiment investigates whether a representational bias exists at the point of encoding by examining choice in light of decision makers’ mental representations of the alternatives, measured with both verbal and nonverbal judgment probes. We found that, when estimates were gauged by the nonverbal probe, participants presented with information in description format (as opposed to experience) had a greater tendency to overestimate rare events and underestimate common events. The choice gap, however, remained even when accounting for this judgment distortion and the effects of sampling bias. Indeed, participants’ estimation of the outcome distribution did not mediate their subsequent choice. It appears that experience-based choices may derive from a process that does not explicitly use probability information.

Sacred values are different from secular values in that they are often associated with violations of the cost-benefit logic of rational choice models. Previous work on sacred values has been largely limited to religious or territorial conflicts deeply embedded in historical contexts. In this work we find that the Iranian nuclear program, a relatively recent development, is treated as sacred by some Iranians, leading to a greater disapproval of deals which involve monetary incentives to end the program. Our results suggest that depending on the prevalence of such values, incentive-focused negotiations may backfire.

We investigated how frequency and amount of punishment affect the decision making of Iranian subjects. In our first experiment, performing a computer-based Persian version of the Iowa Gambling Task (IGT), our subjects scored remarkably lower than their Western counterparts. Moreover, our subjects chose more frequently and more rapidly from decks that had less frequent but larger amounts of punishments in comparison to decks that had more frequent punishments with smaller amounts. In our second experiment, subjects did not differentiate between decks with the same frequency of punishment but with different punishment amounts. However, among decks with the same amount but different frequency of punishment, a significant preference was apparent towards decks with less frequency of punishment. Our results differ from previous studies, indicating a different strategy in risky decision making among healthy adult Iranian subjects, as they show low attention to the amount of punishment and are more concerned with the frequency of punishment.

Third-party punishment has recently received attention as an explanation for human altruism. Feelings of anger in response to norm violations are assumed to motivate third-party sanctions, yet there is only sparse and indirect support for this idea. We investigated the impact of both anger and guilt feelings on third-party sanctions. In two studies both emotions were independently manipulated. Results show that anger and guilt independently constitute sufficient but not necessary causes of punishment. Low levels of punishment are observed only when neither emotion is elicited. We discuss the implications of these findings for the functions of altruistic sanctions.

Researchers frequently argue that within-subjects designs should be avoided because they result in research hypotheses that are transparent to the subjects in the study. This conjecture was empirically tested by replicating several classic between-subjects experiments as within-subjects designs. In two additional experiments, psychology students were given the within-subjects versions of these studies and asked to guess what the researcher was hoping to find (i.e. the research hypothesis), and members of the Society for Judgment and Decision Making (SJDM) were asked to predict how well students would perform this task. On the whole, students were unable to identify the research hypothesis when provided with the within-subjects version of the experiments. Furthermore, SJDM members were largely inaccurate in their predictions of the transparency of a within-subjects design.

The Theory of Planned Behaviour (TpB: Ajzen, 1985; 1991) is based on a utility framework, and the Risk-as-Feelings hypothesis (RaF: Loewenstein, Weber, Hsee, & Welch, 2001) is a feelings-based behavioural model. The TpB and RaF are first compared and contrasted. Two empirical studies investigated the predictive power of consequence-based vs. affect-based evaluative judgements for behavioural intentions: Study 1 (n = 94) applied a regression model to examine the predictive value of a subset of shared variables, unique TpB variables, and unique RaF variables for intentions to have unsafe sex. Study 2 (n = 357) experimentally examined whether intentions are driven by consequences or feelings, in two decision vignettes with opposite qualities: A positive hedonic experience with potential negative consequences (unsafe sex) vs. a negative hedonic experience with potential positive consequences (back surgery). The results supported the TpB by emphasising the role of outcome-expectations in the construction of intentions, and the RaF by showing the importance of affective subcomponents in attitudes.

Impaired decision behavior has been repeatedly observed in schizophrenia patients. We investigated several cognitive mechanisms that might contribute to the jumping-to-conclusions bias (JTC) seen in schizophrenia patients: biases in information-gathering, information weighting and integration, and overconfidence, using the process tracing paradigm Mouselab. Mouselab allows for an in-depth exploration of various decision-making processes in a structured information environment. A total of 37 schizophrenia patients and 30 healthy controls participated in the experiment. Although showing less focused and systematic information search, schizophrenia patients practically considered all pieces of information and showed no JTC in the sense of collecting less pieces of evidence. Choices of patients and controls both approximated a rational solution quite well, but patients showed more extreme confidence ratings. Both groups mainly used weighted additive decision strategies for information integration and only a small proportion relied on simple heuristics. Under high stress induced by affective valence plus time pressure, however, schizophrenia patients switched to equal weighting strategies: less valid cues and more valid ones were weighted equally.

According to Unconscious Thought Theory (UTT: Dijksterhuis & Nordgren, 2006), complex decisions are best made after a period of distraction assumed to elicit “unconscious thought”. Over three studies, respectively offering a conceptual, an identical and a methodologically improved replication of Dijksterhuis et al. (2006), we reassessed UTT’s predictions and dissected the decision task used to demonstrate these predictions. We failed to find any evidence for the benefits of unconscious decision-making. By contrast, we found some evidence that conscious deliberation can lead to better decisions. Further, we identified methodological weaknesses in the UTT decision task: (a) attributes weighting was neglected although attributes were seen as different in importance; (b) the material was not properly counterbalanced; and (c) there was some confusion in the experimental instructions. We propose methodological improvements that address these concerns.