Scandinavian Journal of Psychology, 2000, 41, 275±282 Post-decision consolidation: Group members in different social settings compared to individual decision makers PER EISELE Department of Psychology, Lund University, Sweden Eisele, P. 2000). Post-decision consolidation: Group members in different social settings compared to individual decision makers. Scandinavian Journal of Psychology, 41, 275±282. Two experiments were conducted to examine how making decisions in a 3-member group affects the degree of post-decision consolidation, defined as attractiveness changes in favor of the chosen alternative. Both experiments were conducted in two sessions one week apart. In the first session decision phase), participants estimated the importance of each of four different attributes describing two decision alternatives. They were then shown predetermined attractiveness ratings on each of the attributes and were to decide on the two alternatives, either individually or as a group. In the second session post-decision phase), the participants were to attempt to recall the attractiveness ratings for the attributes as presented to them in session one. In both experiments, significant post-decision consolidation was found for individual decision makers but not for group members. In experiment 2, this result was replicated, no difference in consolidation being found between group members with face-to-face interaction and without. Key words: Decision making, group discussion, social interaction processes, post-decision processes. Per Eisele, FOA, Box 1165, S-58111 Linko Èping, Sweden. INTRODUCTION What happens after a decision has been made is interesting for two reasons. First, the post-decision phase precedes and probably affects the implementation of the decisions made. The study of post-decision processes thus contributes to a better understanding of human decision making. Secondly, the defending of the decision made, or the justification process involved, is in itself of psychological interest. This brings decision research closer to general psychology and creates a possible link to coping strategies in a broader sense. According to Differentiation and Consolidation Theory Svenson, 1992), the chosen alternative has to be viewed as sufficiently superior to its closest competitor before it can be selected. This process of making one alternative better by convincing oneself of it begins in the pre-decision differ- entiation phase leading up to the decision and continues in the post-decision consolidation phase. Both procedural and structural differentiation can be involved. The former includes both decision rule and criterion differentiation. Decision rule differentiation can consist of a change from a simple screening of alternatives to elaborative trade-offs. Structural differentiation includes attractiveness changes in specific attributes in favor of the chosen alternative and devaluation of the non-chosen alternative. Facts, attribute importance and the decision problem itself may also be restructured for the purpose of defending the decision. The consolidation process that follows a decision has the purpose of defending the decision against future threats e.g., negative outcomes or feelings of regret). Why should group members and individual decision- makers differ in their degrees of consolidation? According to Social Comparison Theory, people evaluate themselves in relation to others in order to maintain a positive self-image Festinger, 1954). Could this social evaluation affect evaluation of the choice options? If so, how do group members differ from individual decision-makers in terms of post-decision processes? The diffusion-of-responsibility hy- pothesis see e.g., Forsyth, 1990) would predict a lower degree of consolidation among group members than among individual decision-makers. The need to defend a decision is assumed to decrease as a result of a lowered sense of personal responsibility. In contrast, the familiarization hypothesis Forsyth, 1990) would predict a higher degree of consolidation among group decision makers due to group members encouraging each other in their argumentation and creating an atmosphere of in-group protection that enhances the protection of the favored option. Such enhancement should be stronger in groups where a confirmation pressure exists Janis, 1983). Brehm 1956) and Festinger 1957) assumed that cognitive dissonance invariably follows a decisional choice that people are committed to, since the selected alternative always has some negative features and the rejected alternatives have some positive features. This dissonance gives rise to cognitive restructuring in the direction of bolstering the decision made. Bolstering, according to Janis and Mann 1977), is partly accomplished by upgrading the attractive- ness of the chosen alternative. The gains to be expected are played up and the potential losses played down. Such dissonance-reducing activity results in a change in the decision maker's participantive evaluations of the chosen and the non-chosen alternatives. The chosen alternative comes to be regarded as more attractive and each of the non- # 2000 The Scandinavian Psychological Associations. Published by Blackwell Publishers, 108 Cowley Road, Oxford OX4 1JF, UK and 350 Main Street, Malden, MA 02148, USA. ISSN 0036-5564.