Group decision-making is promoted as more effective than individual decision-making, however, dysfunctional processes such as conformity and polarisation often accompany it. Many group process theorists have suggested that a method for combating the pitfalls of group decision-making is to use deviance. There is little empirical focus, however, on the circumstances under which deviance produces beneficial outcomes for the group, and the processes that underlie these benefits. Furthermore, research has shown that while deviance can lead to increased innovation and creativity within the group, group members often dislike the deviant member and rate group morale as lower due to dissent during the decision-making process. Chapter 1 provides a review of the relevant literature building to the work set out in the empirical chapters.
Chapter 2 (N = 557) examines the effect of deviance on group polarisation and suggests that decision confidence, one of the necessary components of group polarisation, is decreased when deviance is experienced during the group decision-making process, preventing group member attitudes from polarising. In support of this theory, results indicate that decision confidence was lower in groups where there was deviance and, furthermore, that polarisation occurred only in groups where there was no deviance. These results are interpreted in line with relevant theory and a paradigm through which to further investigate the effect of deviance on group-decision-making is suggested.
Chapter 3 provides an information processing account of the influence of deviants in group decision-making and suggests that deviants undermine decision confidence and promote greater elaboration when tasks are difficult. Study 1 (N = 46) manipulated the strength (systematic cue) and gender (heuristic cue) of a job applicant to investigate the effect of a deviant in a difficult task. As predicted, a deviant was associated with lowered confidence, greater elaboration, and higher decision quality, but also decreased group cohesion and task satisfaction. Study 2 (N = 53) investigated the effect of a deviant during a simple task and found the same decrease in group cohesion and task satisfaction, but this time with no increase in elaboration or improvement in decision outcome quality. Results indicate that deviance, when seen as justified, has the potential to reduce the occurrence of prejudice and produce fairer decision outcomes during decision-making.
Chapter 4 (N = 101) again uses an information processing approach to show how deviance improves decision outcomes. It also examines how the perceived position of group members influences whether they are given leeway to voice dissent in order to alleviate the negative consequences identified in Chapter 3. Results suggest that deviance improves decision outcomes through increased reliance on central cues, and participants are more favourable to deviant group members when they are viewed as having high psychological investment in the group. This is consistent with research on group criticism and idiosyncrasy credit and indicates that the position held by deviant group members can alleviate some of the negative consequences associated with deviance in group decision-making.
Chapter 5 (N = 69) manipulates the decision rule under which groups are asked to solve a hidden profile task to determine whether a unanimous decision rule can justify deviance as a necessary process and further alleviate the negative consequences identified in Chapter 3. Results indicate that working under a unanimous decision rule increases the likelihood of shared information and improves the overall decision outcome. Working under a unanimous decision rule is also able to alleviate more of the negative consequences associated with deviance by justifying it as a legitimate part of the task.
Chapter 6 summarises the findings of the empirical chapters in line with the relevant literature and highlights the key findings both in relation to research on the effect of group deviance, and the application of deviance techniques and group decision-making within wider organisational settings.