Driving speed changes and subjective estimates of time savings,accident risks and braking

Participants made decisions between two road improvements to increase mean speed. Time saved when speed increased from a higher driving speed was overestimated in relation to time saved from increases from lower speeds. In Study 2, participants matched pairs of speed increases so that they would give the same time saving and repeated the bias. The increase in risk of an accident with person injury was underestimated and the increase in risk of a fatal accident grossly underestimated when speed increased. The increase of stopping distance when speed increased was systematically underestimated. In Study 3, the tasks and results of Study 2 were repeated with engineering students. When forming opinions about speed limits and traffic planning, drivers, the public, politicians and others who do not collect the proper facts are liable to the same biases as those demonstrated in the present study. Copyright © 2008 John Wiley & Sons, Ltd.     

Predecision conflict and different patterns of postdecision attractiveness restructuring: empirical illustrations from an important real-life decision

This study presents different postdecision consolidation patterns following decisions made under value conflicts. The different patterns were illustrated by case studies of real-life decisions concerning university programs. There were five program alternatives each of which branched into a different professional area. These decisions were very important to the students. The subjects were followed during a year, from a couple of months before they made their choice of program and during several months after the start of the programs. Different postdecision strategies for consolidating a prior decision were derived from Differentiation and Consolidation Theory (Svenson, 1992). The strategies involved the following postdecision attractiveness restructuring patterns. (1) Reversing an attractiveness disadvantage into an advantage on a conflict attribute, (2) Compensating for a disadvantage through increase of an advantage of another attribute, (3) Reversing disadvantage on a conflict and decreasing advantage on non-conflict attribute(s), and (4) Increasing advantage for chosen alternative on all attributes. In addition, (5) downgrading of importance of the conflict attribute or a complete elimination of this attribute is also a possible way of consolidating the prior decision. The results illustrated the above consolidation patterns. A comparison with subjects who made the same decisions but with no value conflict indicated that postdecision consolidation was largely driven by value conflicts at the time of decision in conjunction with the outcome of the decision.     

Perceived level of stress among university undergraduate students in Edmonton, Canada.

A sample of 457 (177 men, 280 women) undergraduate students were surveyed regarding perceived level of stress. Women were more likely than men to report an unacceptable stress level. To reduce stress, women were more likely to indicate a need to limit commitments, exercise, and worry less. Reasons for not reducing stress were lack of time and lack of self-discipline, both of which were reported significantly more often by women. The present data suggest health education interventions are needed to assist students in coping with the stress they experience.     

Cognitive strategies in a complex judgment task: Analyses of concurrent verbal reports and judgments of cumulated risk over different exposure times

Subjects judged the cumulated risk of dying during a year for a set of persons or cases each characterized by the risks during three different periods of risk exposure during the year (e.g., 18 weeks with 2.3 deaths per thousand persons per year of exposure, 28 weeks with 2.5 deaths and 6 weeks with 16.0 deaths per thousand per year). Three main strategies were used for solving the problems: (1) addition of the risk levels, (2) computing the mean of the risk levels, and (3) the most frequently used anchoring and adjustment strategy most closely approximating the normatively correct risk over the year. The first two strategies do not use all relevant information because they neglect the importance of different exposure times. The anchoring and adjustment strategy used all information and was executed in a first stage in which an initial anchor or reference risk was selected followed by a second stage in which this anchor was adjusted according to the remaining information. The process for finding the first anchor was quite flexible, using different principles (e.g., extreme values or similarity) depending on the pattern of cues characterizing each case. Biases in relation to normative theory originated from subjects misunderstanding or simplifying the problem (Strategies (1) and (2)) or the characteristics of the anchoring and adjustment process which resulted in relative overestimation of short-time, high-risk cases. A few subjects, however, all of whom used sequential anchoring and adjustment, succeeded in giving quite accurate estimates.     

Post-decision consolidation in large group decision-making

Decision-makers tend to change the psychological attractiveness of decision alternatives in favor of their own preferred alternative after the decision is made. In two experiments, the present research examined whether such decision consolidation occurs also among individual group members in a large group decision-making situation. High-school students were presented with a decision scenario on an important issue in their school. The final decision was made by in-group authority, out-group authority or by majority after a ballot voting. Results showed that individual members of large groups changed the attractiveness of their preferred alternative from a pre- to a post-decision phase, that these consolidation effects increased when decisions were made by in-group members, and when participants identified strongly with their school. Implications of the findings for understanding of group behavior and subgroup relations are discussed.     

Memories of real-life decisions

Three studies investigated decision makers’ memory representations of choice alternatives in most important real-life decisions. In Study 1, each participant recalled the most important decision that she or he had ever made and rated to what degree a number of characteristics could describe the decisions. In Study 2, the participants were asked to think about an important decision that they had made during the last 7–10 days. In Study 3, the memory representations of decisions of a group of action-oriented participants were compared with those of a group of state-oriented participants (Kuhl, 1983). Characteristics related to standard decision theory, like consequences, values, and likelihood, had high ratings of applicability as well as affect/feeling. When testing the applicability of a circumplex model, the fuzzy-trace theory of memory, and differences between state- and action-oriented decision makers, we found (1) that there was no support for the circumplex model of emotions. Instead, an important decision problem was characterised by both positive and negative affect/emotion and thus, a bipolar mapping was found inadequate; (2) that a comparison of abstract and concrete aspects showed that the abstract characteristics scored higher, thereby supporting the fuzzy-trace theory; and (3) that the prediction that action-oriented participants would score higher than state-oriented participants on the characteristic of activity was not supported. However, state-oriented decision makers rated passivity higher than action-oriented decision makers for the important decision of leaving a partner. State-oriented decision makers used perceptual/cognitive scenario representations to a greater extent than action-oriented participants. Finally, it was stressed that in the development of decision theories it is essential to find theoretical representations as close as possible to how decision makers themselves represent the decisions. The method used in this contribution is focused on the role of memory in decision making and gives further insights into how important real-life decisions are represented by different decision makers.     

Differentiation and consolidation theory of human decision making: A frame of reference for the study of pre- and post-decision processes

Differentiation and Consolidation Theory of decision making models human decision making as an active process in which one alternative is gradually differentiated from other available alternatives. The theory is based on the assumption that it is not sufficient to choose the best alternative, but that a decision involves the selection and creation of a candidate that is sufficiently superior for a decision. This is achieved in differentiation processes which are wholistic, structural or process related. To exemplify, structural differentiation includes both facts and attractiveness restructuring. Following a decision, the theory predicts consolidation processes which work in favor of the chosen alternative. Both differentiation and consolidation are driven by the fact that through experience with the impredictability of the future, a decision maker has learned to prepare for threats against the chosen alternatives. The further this alternative has been differentiated and consolidated, the less the risk of post-decision ambiguity, regret or decision reversal. The study is concluded with references to othee decision theories some of which are viewed as subtheories of Differentiation and Consolidation Theory.