Quality of decisions: Individuals versus real and synthetic groups.

Compared the quality of decisions on 3 economic problems for individuals, 2 forms of real 5-person groups, and 3 synthetic group-decision rules. A total of 185 undergraduates first made decisions as individuals or as group members and then participated in the opposite condition. Real groups with no previous exposure to the problems made better decisions than did groups whose members had previously made individual decisions on the same tasks, and made decisions superior to a plurality synthetic decision rule, but inferior to the "best man" or I. Lorge and N. Solomon's Model A rule (1955). Both types of real groups outperformed individuals. The relationship between decision quality and riskiness of decision alternatives varied in the 3 decision tasks. Real groups with no prior exposure to the task responded to the suggested risk norm more appropriately than did other decision-making units. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency perception of individual and group successes as a function of competition, coaction, and isolation

The frequency perception of successful and unsuccessful outcomes obtained in serial tasks was investigated in two experiments. Subjects were assigned to serial tasks in which the outcome stimuli ("right" and "wrong") immediately followed subjects' responses to each task item. Subjects' perceptual judgment about the number of "rights and wrongs" obtained was requested at the end of the serial task (incidental event perception). In Experiment 1, subjects performing in groups of four were compared with individual performers both in competing and noncompeting (coacting) conditions. In Experiment 2, the influence of verbal communication and competition versus isolation was examined. Significant and predicted differences in frequeency perception were found (a) in group performers as compared with individual performers, (b) in groups with verbal communication as compared with groups without verbal communication, and (c) in competing groups as compared with noncompeting, especially isolated, groups. The frequency perception of success is discussed in the context of impression formation processes, and its impact on person perception and learning is mentioned. A tentative explanation in terms of affective and cognitive processes related to social interaction is submitted.     

Leveraging member knowledge in group decision-making: Expertise, extroversion, and feedback.

This paper focuses on how cooperative groups generate estimates. We investigate how a novel method of increasing the demonstrability of an estimation task, which we call “bridge-building” (i.e., using existing knowledge to address unknown problems), affects the decision-making methods and performance of groups and individuals. We compare this to the effects of providing groups with explicit feedback on member expertise. Results indicate that estimates generated both by groups in the bridge-building condition and groups with feedback were best predicted by a model assuming decisions to be weighted to reflect the accuracy of members on that and all previous estimates. When groups had neither intervention, their decisions were best fit by a model assuming group influence to be a function of member extroversion. Finally, results indicate that the bridge-building manipulation interacts with the type of problem solver generating the estimate such that groups improve whereas the performance of poor individual problem solvers further declines. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Individual and group reward allocation decisions in two situational contexts: Effects of relative need and performance.

Assessed the effects of relative need and performance information on individual and group reward allocation decisions in 2 situational contexts. 320 male undergraduates, as individuals or in 4-person groups, were asked to divide a reward between either 2 workers who had performed a given task (work situation) or 2 students who had qualified for a particular scholarship. Performance and need information (high vs low levels) about each target person were presented. Performance and need information affected allocation decisions differently in the 2 situations. Individual decisions were affected by the need information to a greater degree than were group decisions, but only in the work situation. A social decision scheme analysis of the group decision process showed that the individual/group difference found for the work situation could be accounted for by the plurality/majority decision rule used by groups. Results are discussed in relation to reward allocation and group decision making in general. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Choice behavior in social dilemmas: Effects of social identity, group size, and decision framing.

Social dilemmas appear in 2 basic forms: the public goods (PG) problem, in which the individual must decide whether to contribute to a common resource, and the commons dilemma (CD), in which the individual must decide whether to take from a common resource. The 2 forms of choice dilemma are equivalent in terms of outcomes, but because they involve different decision frames, they are not psychologically equivalent. The present experiment, with 88 undergraduates, examined framing effects on decisions involving use of a common resource pool in a 2?×?2?×?2 (PG vs CD task structure?×?small vs large group size?×?individualistic vs collective social identity) factorial design. That the 2 versions of the decision task were not psychologically equivalent was evidenced both by a main effect of task structure and by interactions involving task structure, group size, and social identity. Overall, Ss kept more of the common resource for themselves under the PG version of the task than under the CD frame. Under the CD structure, group size had no effect on choice behavior, but in the PG version, Ss in large groups kept more than did individuals in small groups. As the resource pool was depleted, the social identity manipulation had opposite effects for large groups under CD and PG frames. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working-memory capacity and the control of attention: The contributions of goal neglect, response competition, and task set to Stroop interference.

Individual differences in working-memory (WM) capacity predicted performance on the Stroop task in 5 experiments, indicating the importance of executive control and goal maintenance to selective attention. When the Stroop task encouraged goal neglect by including large numbers of congruent trials (RED presented in red), low WM individuals committed more errors than did high WM individuals on the rare incongruent trials (BLUE in red) that required maintaining access to the "ignore-the-word" goal for accurate responding. In contrast, in tasks with no or few congruent trials, or in high-congruency tasks that followed low-congruency tasks, WM predicted response-time interference. WM was related to latency, not accuracy, in contexts that reinforced the task goal and so minimized the difficulty of actively maintaining it. The data and a literature review suggest that Stroop interference is jointly determined by 2 mechanisms, goal maintenance and competition resolution, and that the dominance of each depends on WM capacity, as well as the task set induced by current and previous contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparative study of individual, majority, and group judgment.

"The performance of individuals working alone, under majority rule, and as members of discussion groups were compared on a complex intellectual task… . The results indicated that:… Majority decisions, when deadlocks are evenly divided between right and wrong, decisions, are not significantly different from those made by the average individual and are inferior to those of the best members of the group working alone… . Group decisions, reached through cooperative deliberation, are significantly superior to decisions made by individual members working alone and to majority rule." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expert role assignment and information sampling during collective recall and decision making.

Previous research has found that decision-making groups do not effectively pool unshared information. This study examined how personal expertise facilitates the mentioning and validation of unshared information in collective recall and decision-making groups by increasing members' awareness of who holds what types of information. Assigned expertise increased substantially the proportion of unshared information mentioned during both collective recall and decision-making tasks. Two results supported the hypothesis that assigned expertise provides validation for the recall of unshared information. When expertise was assigned, (1) more of the unshared information mentioned during the recall task was retained on the collectively endorsed written protocol, and (2) unshared information that was mentioned in discussion was more likely to be correctly recognized by members after group interaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task design, outcome interdependence, and individual differences: Their joint effects on effort in task-performing teams (Commentary on Huguet et al., 1999).

Analyses of effort problems in groups, like that of P. Huguet, E. Charbonnier, and J.-M. Monteil (see record 1999-13879-004), have implications for how tasks are designed for work teams, how outcomes are distributed, and the complex interrelations between personality characteristics of team members and their response to the work situation. Whereas group members working on uninvolving tasks tend to loaf, when task interdependence is high and the goals are meaningful individuals in groups often expend more rather than less effort. Moreover, whereas the group's outcomes are sometimes determined by the qualities of the individuals in the groups, in other cases the experience of working collectively changes individuals (e.g., individuals who prefer to work alone change to prefer working in groups after experiencing the benefits of working collectively). In consequence, findings about individual differences are often the hardest to apply when making decisions about work group design and composition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of social loafing in predeliberation decision making.

The relationship between social loafing and decision making was examined in an individual predeliberation thinking task. Participants (N?=?189) were asked to read information and make decisions ostensibly in order to make a future individual or group decision. Decision type (intellective or judgmental) and anticipated group size (individuals or 4 or 8 members) were manipulated to examine their effect on information recall. Individuals who anticipated working alone or who believed they were making intellective decisions recalled more information than did those who anticipated working in groups or who believed they were making judgmental decisions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of member status differences and task type on group consensus and member position change.

Investigated how status differences among discussants, together with the type of task, influenced the social-decision schemes that guide consensus and group performance among 345 male undergraduates. Members of 3-person groups received feedback from a test of decision-making ability that created 1 of 3 task-relevant status distributions (conditional, 2-3-4; outstanding, 2-2-5; and equal, 3-3-3 [larger values indicate higher status]) and reached consensus decisions on 1 intellective task (a mystery problem) and 2 judgmental tasks (personnel selection and allocation of resources). The latter 2 tasks had no correct answers and were particularly susceptible to normative factors. The particular social-decision scheme model (reformulated to allow for individual differences) that successfully predicted group decisions emphasized both task and status distribution: Intellective problem responses were predicted by a truth-wins model in the equal and conditional power conditions and a power-wins model in the outstanding power condition. Discussion-induced personal change (individual preferences before–after discussion) was highly dependent on status level, except for the intellective task, for which change was independent of status, but greater in overall magnitude than for the other 2 tasks. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lexical, sublexical, and implicit memory processes in healthy young and healthy older adults and in individuals with dementia of the Alzheimer type.

Five groups of participants—healthy young, healthy young-old, healthy old-old, very mildly demented, and mildly demented individuals of the Alzheimer type (DAT)—participated in a 2-phase experiment that entailed a rhyme judgment task followed by a lexical decision task, in which half of the stimuli were earlier presented in the rhyme judgment task. The results of the rhyme task indicated that healthy young and older adults did not produce an influence of word frequency on rhyme decisions. However, the 2 groups of DAT individuals produced large word-frequency effects primarily for the nonrhyming pairs. The results of the lexical decision task indicated that (a) repetition facilitated lexical decisions to words, whereas there was evidence of inhibition for nonwords; and (b) there was an increasing influence of word frequency across the 5 groups of participants. The results are interpreted with respect to attentional control of appropriate (lexical and sublexical) processing pathways and the nature of processes that are disrupted and those that remain uninfluenced in healthy aging and DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

No pain, no gains: Negative mood leads to process gains in idea-generation groups.

Research has consistently demonstrated that individuals tend to outperform groups on idea-generation tasks (e.g., Mullen, Johnson, & Salas, 1991). However, mood states have the capacity to alter the coordination and motivation of group members, leading to performance gains or performance losses. In this experiment, individuals and 3-person groups generated slogans for a fictitious company after experiencing a positive or negative mood induction. Contrary to previous research, negative mood groups in our study actually generated slogans that were more creative than those produced by negative mood individuals. No differences emerged for positive individuals and groups. In the negative conditions, the effect of level of analysis (individual vs. group) on creativity was mediated by persistence on the slogan-generation task. Results are presented in the context of feelings-as-information (N. Schwarz & G. L. Clore, 1988). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in group task performance.

115 female and 118 male psychology students worked individually or in 3-person same-sex groups on a production task (requiring the generation of ideas) or on a discussion task (requiring group members to reach consensus concerning their evaluation of an issue). Because the content of the tasks was carefully selected not to favor the interests or expertise of one sex over the other, no sex differences were expected when Ss worked individually. Results show no gender differences in individual production performance. Only the creativity of the discussion problems was affected by gender; males working individually generated more creative solutions than did females. Consistent with prior research, males in groups generated more solutions to the production problems than did females; females in groups generated higher quality solutions to the discussion problem than did males. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reducing the performance-cue bias in work behavior ratings: Can groups help?

The authors examined whether the performance-cue bias can be reduced by relying on groups as raters. Study participants (N = 333) were provided with feedback regarding the performance of a workgroup and, after observing the group, assigned to an individual or group rater condition to complete a behavioral rating instrument. Results revealed that when provided with positive (vs. negative) feedback, individuals attributed more effective and fewer ineffective behaviors to the workgroup; however, group ratings were unaffected by the feedback. In addition, feedback biased the decision criteria and false alarm rates of individuals but not of groups. Discussion of when groups may attenuate versus amplify bias in performance appraisal judgments emphasizes 2 key elements--bias magnitude and task perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Collective memory: collaborative and individual processes in remembering

Two experiments compared collaborative and individual recall. In Experiment 1, participants encoded pictures and words with a deep or shallow processing task, then recalled them twice either individually or collaboratively. Collaborative groups recalled more than individuals, but less than nominal groups (pooled individuals), thus exhibiting collaborative inhibition. However, group recall appeared to be more stable over time than individual recall. Groups and individuals both showed a picture-superiority effect, a level-of-processing effect, and hypermnesia. In Experiment 2, participants recalled the story "War of the Ghosts" (from F. C. Bartlett, 1932), and again collaborative groups recalled more than individuals, but less than nominal groups. Both the individual and collaborative recalls were highly organized. There was evidence that the collaborative groups tended to rely on the best individual to a greater extent in story than in list recall. Possible social and cognitive mechanisms are considered.     

Cognitive and consensus processes in group recognition memory performance.

This experiment applies signal detection theory and social decision schemes to investigate the potential impact of information pooling, error correction, and effective decision-making processes in the general finding that groups perform better than individuals on memory tasks. Groups and individuals completed a true/false recognition test regarding material presented in a videotaped simulated job interview. Various indexes of memory performance indicated that each of the processes contributed to the superiority of group recognition memory performance. Social decision scheme analyses indicated that the plurality-correct-wins decision scheme was the best summary of the decision process. Subsequent analyses suggested that the confidence that group members held in their initial preferences influenced the group decision process. Discussion emphasized the impact of consensus, correctness, and confidence on group memory performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of task difficulty and task uniqueness on social loafing.

Previous research has shown that Ss taking part in either physical or cognitive tasks alone and/or in groups put out less effort in groups, an effect called "social loafing." This loafing can be eliminated by telling Ss that their individual outputs can be identified even when they perform in groups. In 4 experiments with 304 undergraduates, the authors demonstrated that loafing can also be reduced either by increasing the difficulty (challenge) of the task or by giving each S a different task to perform. Despite the fact that these Ss felt as unidentifiable as Ss working on the typical loafing task, they performed as well as Ss with identifiable outputs. It is concluded that when Ss perceive that they can make a unique contribution to a group effort, social loafing is reduced even if individual contributions remain unidentifiable. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interpersonal relationships and task performance: An examination of mediation processes in friendship and acquaintance groups.

This study used multiple methods to examine group processes (information sharing, morale building, planning, critical evaluation, commitment, monitoring, and cooperation) that mediate the effect of relationship level on group performance. The study uses a 2 by 2 experimental design, crossing relationship (friendship vs. acquaintance) as a between-subjects variable and task type (decision making vs. motor) as a within-subject variable. Fifty-three 3-person groups participated in the study, and data from 4 types of measurement were used to analyze the mediating processes between relationship level and task performance. Friendship groups performed significantly better than acquaintance groups on both decision-making and motor tasks because of a greater degree of group commitment and cooperation. Critical evaluation and task monitoring also significantly increased decision-making performance, whereas positive communication mediated the relationship between friendship and motor task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The randomization procedure in the study of categorization of multidimensional stimuli by pigeons

Pigeons categorized rectangles varying in both height and width in an adaptation of a method used by Ashby and colleagues for the cognitive and neuropsychological analysis of human decision bounds for ill-defined categories. Optimal decision bounds were defined in a stimulus space in which the point (x,y) corresponded to a rectangle with width x and height y. Four tasks defined the following 4 optimal bounds: x = y, x = c, x = y + d, and (x-a)2 + (y-b)2 = r2, where a, b, c, d, and r were constants given by a task. Estimated decision bounds for individual pigeons conformed approximately to the optimal decision bound in each of the 4 tasks. The new method suggests a way to (a) integrate the disparate literature on ill-defined visual concepts and on optimal performances in nonhuman animals; (b) compare how humans and nonhuman animals categorize ambiguous, multidimensional configural stimuli; (c) model how nonhuman animals categorize naturalistic stimuli; and (d) infer that pigeons' categorizations of naturalistic stimuli may be remarkably close to optimal.