Group Performance Depends on the Majority Rule

Abstract

Some group decisions require a two-thirds or three-quarters majority of the people voting; others require only a simple majority. Does the accuracy of a group's decision making depend on which majority rule is used? A signal detection theory analysis was used to answer this question. Each member of a group was presented with a noisy display of either a signal or a nonsignal, and then each member cast a yes or no vote for the existence of a signal. The group decision was determined by a majority rule of the members' votes. Normative groups and groups of 5 or 7 people exhibited the same behavior: Performance was best when the group used a simple-majority rule and decreased when the group used more stringent rules. The worst performance was produced by a unanimous rule. Some group members adopted more liberal response criteria when the majority rule was made more stringent.

The wisdom of crowds for visual search

“…Although some groups seem to have leaders who make decisions alone on behalf of their groups (17,(21)(22)(23), it is difficult for individuals to outperform even simple aggregations of the entire group's individual judgments (4,7,9,10,19,(24)(25)(26). Perhaps that is why humans often make important decisions as a group (27-29), even if the only expedient (30, 31) but effective (24, 31-34) group decision mechanism is to use the simple majority voting rule (35).…”

Regulatory Focus and Self-Construal as Determinants of the Majority Rule in Individual Decision Making

“…First, the possible value of the paper may not lie in the scope of comparing the majority rule with these choice strategies that would predict the opposite results (cf., Baillon et al, 2016;Hastie & Kameda, 2005;Miller, 1985;Sorkin et al, 1998;Taylor et al, 2013) or with these compatible strategies (e.g., the additive or equal-weighted rule); rather, we aim to show that certain situations facilitate the use of the majority rule. Second, different from these experimental designs with repeatedly consequential decisions between options, which enabled to test the coherence of behavior according to axiomatic criteria when using the majority rule (e.g., Birnbaum & Diecidue, 2015), we applied a single choice task, which failed to examine any refutation of such axioms (e.g., the transitivity axiom) and to consider the effect of random errors on the choice results.…”

“…The majority rule is also examined as a pivotal moderating factor, which influences the relationship between intra-team process conflict and cognitive diversity, namely rational and spontaneous styles (Fitzgerald, Mohammed, & Kremer, 2017), and between social diversity and the efficacy of group decision making (McGrimmon, 2011). Compared with another commonly used group decision method of social choice, the unanimity rule (rule by consensus), the majority rule shows an advantage in arriving at a quicker decision (Taylor, Hewitt, Reeves, Hobbs, & Lawless, 2013), indicates a better performance accuracy (Sorkin, West, & Robinson, 1998), counteracts the negative effects of egoistic motivation on joint outcomes in asymmetrical negotiations (Beersma & De Dreu, 2002), results in different decisions when group members are informed of one another's preference for the options (Miller, 1985), leads to weaker communication effects (Baillon, Bleichrodt, Liu, & Wakker, 2016), and achieves less decision implementation and outcome satisfaction (Marsden & Mathiyalakan, 2003;Mohammed & Ringseis, 2001). Overall, previous work from a scattering of empirical and anecdotal sources provided credible evidence in support of the majority rule as a pervasively robust norm in group judgment and decision making.…”

Modeling Memory Processes and Performance Benchmarks of AWACS Weapons Director Teams

“…The contributions of team members are the sensitivity and accuracy of the judgments they make for the memory responses. The combination aspect of signal detection theory reflects the models that integrate the responses or information available to the team members (Sorkin, West, & Robinson, 1998). The integration model of signal detection theory also represents the information pooling thought to contribute to the superiority of team perfornance.…”