MULTIPLE DECISION MAKERS

Group decision making is significantly more complex than are decisions made by individuals. Several new issues arise: combining multiple beliefs and preferences, social interac­tion of decision makers, and conflict and cooperation. In this section we examine research that addresses these issues in terms of group decision making for certain and uncertain out­comes, technology designed specifically to aid group deci­sion making, and negotiation between two parties.

) Group Decision Making

Two new phenomena have been discovered in group decision making: groupthink and the risky shift. Janis (1972) defined S^uptkink as "a mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when foe members' strivings for unanimity override their motiva­tion to realistically appraise alternative courses of action" (P- 9). A classic case example is the failed Bay of Pigs inva-^s'on, in which the American military sent Cuban exiles to overthrow the dictator Fidel Castro. These groupthink deci-^slons are characterized by highly cohesive groups that are under high stress from an external threat and have low self-^esteem due to an earlier failure or decision difficulty. Several toer attributes may also contribute to groupthink: an illusion ⁰¹ ^vulnerability, collective rationalization, belief in the in­dent morality of the group, insulation, lack of impartial

Multiple Decision Makers 509

leadership, direct pressure on dissenters, stereotypes of out-groups, and lack of a decision-making procedure. However, note that merely increasing group familiarity alone is not suf­ficient to cause groupthink: Watson, Michaelsen, and Sharp (1991) found that groups who spent more than 30 hours on decision-making tasks were more effective than were indi­vidual decision makers.

The risky shift (Stoner, 1961) is the tendency for decisions made by groups to be more risk seeking than would be pre­dicted by the individual members' risk preferences. However, as Bazerman {1998) pointed out, most of the studies finding the risky shift used Stoner's (1961) Choice Dilemma Question­naire (CDQ) method. Other studies using different methodolo­gies have found either no shift or a cautious shift (i.e., more risk averse).

Are groups better or worse decision makers than individu­als? The answer depends on the situation and decision to be made (and, of course, on the criteria for "good"; in many set­tings a technically inferior decision to which the whole group is agreed may be an excellent choice). There is no clear pat­tern of group effects in either reducing or increasing decision biases. The hindsight bias was reduced slightly with groups compared to individuals (Stahlberg, Eller, Maass, & Frey, 1995), although Bukszar and Connolly (1988) found no ef­fect. However, groups were even more affected than individ­uals by the representativeness heuristic in a base-rate (cab) problem (Argote, Seabright, & Dyer, 1986). And groups, like individuals, appear to be biased in their information search {Schulz-Hardt, Dieter, Luethgens, & Moscovici, 2000). Tindale (1993) argued that group effectiveness depends on the demonstrability of the solution. If there is a solution that one or more members of the group can demonstrate as the correct answer, then the group will usually adopt this solu­tion. However, if the solution cannot be easily demonstrated (as in the cab problem), then the group decides by majority rule (Tindale & Davis, 1985). Because most individuals ne­glect base rates in situations such as the cab problem, the ma­jority will also fall prey to this bias. Tindale (1993) presented data in which decision biases are reduced or enhanced with groups as compared to individuals.

Kerr, MacCoun, and Kramer (1996) reviewed studies in­vestigating decision biases at both the individual and the group level. They also concluded that the strength of decision biases can either be lower, equal to, or higher for groups as compared to individuals depending on the type of decision, the initial values of the individuals, and how individual values are aggregated into group decisions. They organized the various results into a formal model of group decision making called the social decision scheme (SDS) model (Davis, 1973; see the special issue of Organizational Behavior and Human

510Judgment and Decision Making

Decision Processes, 1999, on this topic). This model provides a framework for answering the question about how individual values are aggregated into a group decision and what decisions will emerge given different decision rules such as "majority wins," "truth wins," or "equiprobability," in which every op­tion has an equal probability of being selected as long as it has a single advocate. For example, Whyte and Sebenius (1997) found that groups did not debias individual estimates that were improperly and inappropriately anchored. Using SDS methodology, the authors showed that group estimates were based on the majority point of view that was biased before group discussion began.

Although it is unclear whether groups are better or worse at making decision than individuals, there are certain conditions in which groups can increase decision-making quality. Sev­eral studies of heterogeneous groups (in terms of many attrib­utes such as personalities, gender, attitudes, and experience) indicate that heterogeneity is positively related to creativity and decision effectiveness (Jackson, May, & Whitney, 1995). Guzzo and Waters (1982) found that the quality of group de­cisions and the number of diverse alternatives increased when expression of emotion was delayed until alternative solutions were discussed. They suggested that early expression of emo­tions may reduce the group energy and narrow the range of accepted ideas. Under time pressure, quality of decisions generally decline; task cohesion can help groups maintain decision quality at a level comparable to low time pressure situations (Zaccaro, Gualtierei, & Minionis, 1995).

Date: 2016-03-03; view: 842