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Risk-defusing operators (RDO) are actions that reduce risk, to be enacted either before a negative event occurs (pre-event RDOs) or afterwards (post-event RDOs). For post-event RDOs, detection probability of the negative events is relevant. Regulatory focus theory suggests that promotion-oriented individuals – independent whether it is a personal disposition or favored by situational cues – should focus on chances to succeed and therefore choose post-event RDOs more likely than prevention-oriented individuals who are likely to focus on possible failures and means to avoid them. In two experimental studies, we examined effects of detection probability and regulatory focus as a state variable on the choice of post-event RDOs. Results replicate findings that the likelihood to choose post-event RDOs increases with increasing detection probability of the negative events. Contrary to expectation, no clear effects of regulatory focus were found. Exploratory analyses showed some evidence that successful manipulation of regulatory focus might influence RDO choices if tasks are highly relevant for decision-makers.

Under justification pressure, the decision maker knows in advance that the decision has to be justified to somebody afterwards. The effect of justification pressure on the search for risk defusing operators (RDOs) and the role of RDOs in the justification texts were investigated. An RDO is an action intended by the decision maker to be performed in addition to an otherwise attractive alternative to decrease the risk. As predicted, in Experiment 1 participants (60 non-students) under justification pressure searched more RDOs. Additionally, in Experiment 2 (80 non-students) RDO search success was varied. Under justification pressure, persistence of RDO search was higher when no RDO could be detected. In the justification texts, the existence or non-existence of RDOs played a prominent role. Searching for RDOs supports people in their goal to make a good decision and in their attempt to convince the addressee of their justification that the decision was good.

The paper investigates predecisional information search in risky decisions, specifically information concerning the probability of a negative outcome and whether a risk-defusing operator (RDO) is available. Experiment 1 (54 participants) tested the hypothesis that search for such information is triggered by expectations that it can be obtained in the situation. Cues for the availability of information were manipulated. It was predicted that cues mentioning possible information sources raise expectations and consequently increase search activity. Furthermore, gambles were expected to differ from other real world contexts, with lower expectations for RDOs and higher ones for probabilities. The Method of Active Information Search was employed. The number of questions asked about probability and RDOs in different conditions confirmed the hypotheses. Experiment 2 (36 participants) ruled out the alternative interpretation that the expectation to actually find favorable probabilities or applicable RDOs respectively, rather than the expectation to obtain information, determined information search.

This study investigated the functional neuroanatomy of the anterior medial prefrontal cortex (aMPFC). Previous studies have shown that the aMPFC is involved in evaluative judgment and self-referential processes. Specifically, different sections of the aMPFC are differentially influenced by attention demanding processes. Whereas the dorsal section is supposed to be involved in self-referential processes, the ventral section is assumed to be attenuated during attention demanding processes. The present study investigates the involvement of the dorsal and ventral aMPFC in evaluative judgment by using functional magnetic resonance imaging with spin-echo echo-planar-imaging. Processes involved in evaluative judgment are attention-demanding, self-referential and activate regions in the dorsal and ventral section of the aMPFC. Attention demanding tasks do not necessarily lead to an attenuation of the ventral section of the aMPFC, a region mainly involved in emotional and affective processing.

Most experimental results in research on risky decisions have been obtained with lotteries. Choices between lotteries differ in many respects from natural risky decision tasks. Furthermore, the mode of information presentation in gambling experiments is very different from natural situations. In our experiment, 32 non-students made choices in two naturalistic risky decision tasks. The mode of information presentation was varied: Complete information presentation (as common in gambling experiments) vs. Method of Active Information Search (the subject gets a basic description of the task, and has to ask questions to receive additional information). In naturalistic tasks, probability was used less often than expected from classical decision theory, whereas the search for new alternatives, worst-case plans and control considerations were more relevant. The type of information presentation had a distinct effect. With Active Information Search, only a minority of subjects was interested in probabilities. Precise probabilities were used solely in the condition with Complete information presentation.

In a multistage investment task the decision maker attempts to increase the capital by investing some part of it in several trials in a risky opportunity. In the present extension of this task, the decision maker can buy protection for any part of the invested capital. In an experiment with 60 subjects, the effect of the joint variation of the probability of winning and the cost of protection was investigated in the Breeding Lizards task. The proportion of invested capital increased with an increasing probability of winning as in former experiments, but was independent from the cost of protection. Contrary to expectations, the percentage of the invested capital which was protected was not affected by the probability of winning and the cost of protection. A certain amount of wasting behavior was observed. The results are discussed and compared with the behavior prescribed by an optimal strategy.

Process models of decision making usually give very good results when it comes to “explaining” afterwards how a concrete decision process was constructed (retrodiction). The situation, however, is not as satisfactory if we look at predictions. This relative weakness is not an inherent property of process models. The problem is that if one makes all the necessary specifications the model becomes so complex that it is practically impossible to work out predictions over a wider range without a tool such as simulation, even if the model is formulated in some kind of formal language. My argument is that simulation may offer a solution to the problem. The representation of a process model by a working computer program enables, relatively easily, the computation of broad range predictions, and forces the scientist to formulate the model precisely. In this article I use the Chunking-by-Similarity Model as an example. Following the introduction to this model I first present some theoretical considerations concerning the simulation of a psychological theory. Then I discuss some important steps in the simulation of a theory in greater detail. I conclude that in spite of some problems which must be dealt with when a psychological process model is simulated, simulation is a powerful tool which can be used to improve the work with process models.

In a multistage, risky investment task the decision maker tries to increase the capital by investing some part of it in a series of trials. It is assumed that the decision maker will select a stake which results in a tolerable perceived risk as well as an acceptable win. In Experiment 1 (40 non-students) the effects of the joint variation of the winning factor (return rate) and the probability of winning, and of the start capital wereinvestigated in the Breeding Lizards task. Experiment 2 (60 non-students) was designed to replicate the result of Experiment 1 concerning the winning factor with a bigger difference between the two winning factor conditions, and to test the effect of three different cover stories for the abstract investment task. As predicted, a higher winning factor did not result in higher percentage stakes, whereas a higher probability of winning did. Besides the mean percentage stakes, other dependent variables were analyzed. In none of the dependent variables was a difference between the three cover stories detected. The results are discussed.

This study investigates which formal principles govern subjective probability, and whether the validity of these principles depends on age. Two types of tasks were administered to 144 subjects from 3;8 to 19 years: a gambling task (with objective probabilities) and a sporting task (without objective probabilities). Six formal principles of the mathematical concept of qualitative probability (a nonnumerical concept based on ordinal scale properties) were tested. Results indicate that these principles are valid as principles of subjective probability for all age groups. Only the youngest age group (4 years or younger) had a smaller degree of confirmation.