Lorne G. Hulbert

Groupdrink: the effects of alcohol on intergroup competitiveness.

Alcohol is often consumed in group settings. The present article examines the effect of alcohol on intergroup competitiveness through the use of a prisoners dilemma game. One hundred fifty-eight college students participated in the study, either individually or as a member of a 4-person experimental single-sex group. Participants consumed either alcohol (1.13 g ethanol/kg body weight) or a placebo. Results show no effect of alcohol on cooperative choice within individuals. However, groups were significantly less cooperative after consuming alcohol than they were after consuming a placebo. In addition, after consuming alcohol, groups were less cooperative than were individuals. Results are discussed in terms of the way alcohol may affect focus of attention on group-level cues.

The Effect of Group Decision Making on Cooperation in Social Dilemmas

A robust finding in social dilemma research is an increase in individual cooperative choice following group discussion about the dilemma. To elaborate the idea that this effect arises from the development of within-group consensus, groups of six made explicit group decisions about their subsequent individual choice. Perceived demonstrability of cooperativeness in the dilemma was manipulated through changes both to instructions and the incentives of the dilemma. As demonstrability decreased, so did the proportion of groups deciding to cooperate, leading to a reduction in the group discussion effect. Social decision scheme analysis supported the demonstrability-group decision hypothesis. The interaction between demonstrability, individual opinions and group process is proposed to explain the group discussion effect.

The Plaintiff Bias in Mock Civil Jury Decision Making: Consensus Requirements, Information Format and Amount of Consensus

The effect of the normatively based plaintiff bias (favoritism toward an individual suing a corporation) on decision making was assessed for six-person mock juries that made decisions, or merely discussed the case, or for individual jurors. Decision makers also received information in either tables or graphs but there was no effect of this manipulation. It was predicted that groups would award more money than individual decision makers, and that the effect of the plaintiff bias on individual opinions would be strongest when groups discussed but did not decide. Group decisions were higher than individual decisions, and examination of the amount and perception of consensus achieved in groups indicated that the bias affected opinions when groups discussed, but not when groups decided. These results demonstrate the effects of the norm on intermember social influence and opinion change absent similar effects arising from the process of group decision making. The results are integrated with existing research on related issues.

Procedural and Agenda Effects on Political Decisions by Small Groups

Many if not most political decisions are made by groups. Small group caucuses often help to choose political candidates, legislative bodies (e.g., Congress) decide which laws to enact, and leaders with their advisors (e.g., U.S. Security Council) make strategic and military decisions. Although some groups are just advisory, where responsibility for the final decision falls on a single individual (leader), many group decisions require a group-level response and are based on decision rules that are meant to lead to fair and representative decisions (Grofman & Owen, 1986). For example, many legislative bodies follow majority decision rules—simple majorities decide most decisions and 3/5ths or 2/3rds majorities are required for major or particularly important decisions. Such group decision rules are used to insure that decisions represent the preferences shared by most of the group members (Kameda, Tindale, & Davis, in press; Tindale & Kameda, 2000), and are often perceived as the “fairest” or most just ways of making group decisions (Tindale & Davis, 1983).