Task bias and the accuracy of judgment: Setting a baseline for expected group performance

When a judgment task evokes unbiased estimates (i.e. the errors in individual judgments are distributed randomly around the true value), mathematical aggregation of individual estimates, even by a simple arithmetic mean, often will outperform all group members. However, when a task evokes biased estimates, mathematical aggregation does not perform so well. In this study, simulated data were accumulated to specify the expected' accuracy of mathematical aggregation relative to the accuracy of observed judgment of individual group members under varying conditions of task bias. Three types of judgment tasks were employed: (1) single-estimate, holistic tasks, (2) multiple-estimate, ranking tasks, and (3) multi-cue, decomposed tasks. Findings indicated across all task types that a large percentage of judgment-making group estimates formed strictly by computing the arithmetic mean of individual estimates performed better than their most capable members when a judgment task evoked little or no bias, a result particularly pronounced for ranking tasks. When the task was more greatly bias-evoking, a large percentage of parallel groups performed more poorly than average (or median) members, again a pattern more starkly evident for ranking tasks. These results suggest that the extent to which a judgment task evokes bias in a population of prospective group members is an important explanatory variable deserving much greater attention in the study of group performance. For example, an assertion about the efficacy of a particular group intervention based on a reliable demonstration of group performance as accurate as the most capable members may be unfounded when a task evokes no bias, since the baseline standard under such conditions should be much higher. By selecting tasks and populations that jointly produced highly biased estimates, researchers can lower the performance floor enough to detect (with reasonably small samples of groups) experimental effects should they occur.     

Heterogeneous heterogeneity by default: Testing categorical moderators in mixed-effects meta-analysis

Categorical moderators are often included in mixed-effects meta-analysis to explain heterogeneity in effect sizes. An assumption in tests of categorical moderator effects is that of a constant between-study variance across all levels of the moderator. Although it rarely receives serious thought, there can be statistical ramifications to upholding this assumption. We propose that researchers should instead default to assuming unequal between-study variances when analysing categorical moderators. To achieve this, we suggest using a mixed-effects location-scale model (MELSM) to allow group-specific estimates for the between-study variance. In two extensive simulation studies, we show that in terms of Type I error and statistical power, little is lost by using the MELSM for moderator tests, but there can be serious costs when an equal variance mixed-effects model (MEM) is used. Most notably, in scenarios with balanced sample sizes or equal between-study variance, the Type I error and power rates are nearly identical between the MEM and the MELSM. On the other hand, with imbalanced sample sizes and unequal variances, the Type I error rate under the MEM can be grossly inflated or overly conservative, whereas the MELSM does comparatively well in controlling the Type I error across the majority of cases. A notable exception where the MELSM did not clearly outperform the MEM was in the case of few studies (e.g., 5). With respect to power, the MELSM had similar or higher power than the MEM in conditions where the latter produced non-inflated Type 1 error rates. Together, our results support the idea that assuming unequal between-study variances is preferred as a default strategy when testing categorical moderators.     

Macro- and microlevel factors related to sense of community: The case of temporary neighborhoods in Israel

This study examines macro and micro factors influencing the development of sense of community (Davidson & Cotter, 1980) in two different populations (immigrants and veterans) in new temporary neighborhoods in Israel. At the macrolevel, the major factors examined were population size, population density, number of dwelling units in the site, urbanity of the area, ethnic heterogeneity, and peripheriality of the region. Three kinds of variables were examined on the microlevel: (a) personal attitudes: evaluation of the dwelling unit and satisfaction with public services; (b) social networks; and (c) sociodemographic characteristics. Data were collected from 242 immigrants from the former USSR and from 60 Israeli veterans, residing in 5 different sites. Two different patterns of predictors of sense of community emerged in the two different samples. In the veteran sample, only one macrolevel variable entered the stepwise analysis equation: the number of dwelling units in the site. In the immigrant sample, three significant microlevel factors entered the equation: evaluation of the dwelling unit, external network, and age. The data thus suggest that the major determinant factors underlying sense of community vary for different groups of people. The paper is based on a study initiated and financed by the Ministry of Housing and Construction, the Unit of Social Policy, Israel.     

Action Generalization Across Group Members: Action Efficiency Matters

Actions are usually generalized among social group members. Importantly, the efficiency of an action with respect to achieving an external target determines action understanding, and it may have different degrees of social relevance to social groups. Thus, this study explored the role of action efficiency in action generalization. We used computer animations to simulate actions in social groups initiated by visual action cues or category labels, and we measured differences in response times between identifying actions that were and were not consistent with group members, without explicit requirements regarding generalization. It was found that in both visually introduced and explicitly labeled social groups, when the group members acted inefficiently toward the external object, perceivers identified group-consistent actions faster than group-inconsistent actions, indicating that the exemplars' common inefficient actions are generalized to the unknown ingroup member, accordingly facilitating the identification of expected consistent inefficient action (Experiment 1). As this effect was not present when removing social group cues, it was determined to be specific to social groups (Experiment 2). Importantly, such generalization was not observed when the identical action was deemed efficient toward the external object (Experiment 3) and was specific to the demonstration of the action being completed by multiple group members rather than being repeated twice by one group member, supporting the group-based inference and ruling out the possibility of the increased memorability of inefficient actions leading to more generalization relative to efficient actions (Experiment 4). Therefore, the efficiency of an action bounds the generalization of the action across social group members through a process that is spontaneous and implicit. This constrained action generalization may be due to inefficient actions being represented as culture-specific conventional forms.     

Perceptions of War Trauma and Healing of Marital Relations Among Torture-surviving Congolese Couples Participating in Multicouple Therapy

Citizens of the Democratic Republic of Congo (DRC) experienced widespread torture during national wars between 1998 and 2003. Couples who survived and stayed intact suffered tremendous relationship stress. This study used a critical ethnography framework to explore the prewar, wartime, and postwar experiences of 13 torture-surviving couples who participated in a 10-session Torture-Surviving Couple Group in 2008 in the DRC. The group was designed to address the relational effects of torture and war trauma. Participants reported profound negative effects of the war on their relationships; mostly positive experiences during the group, including marital and peer connection and relationship growth; and a number of improvements in their relationship after the group. Implications include support for the use of relational interventions informed by both treatments for traumatic stress and couple approaches to promote trauma healing. Future directions call for increased funding, research, training, and clinical action to treat the effects of traumatic stress on relational family dynamics.     

The relationship between peer servant leadership,social identity,and team cohesion in intercollegiate athletics

Servant leadership is characterized by a leader’s emphasis on serving their followers first. Within the sport context, servant leadership has been studied primarily in coaches and has been associated with positive athlete outcomes, such as increased athlete satisfaction, motivation, and performance. However, the impact of servant leadership from an athlete perspective (e.g., formal team captains) has been underexplored. As such, the purpose of the present study was to examine the relationships between peer servant leadership, cohesion, and social identity within intercollegiate athletes. Two hundred and eighty-eight Division I and Division III NCAA intercollegiate athletes participated in the present study (female n = 165; male n = 123; M_age = 19.41, SD_age = 1.09) and completed the Revised Servant Leadership Profile for Sport (RSLP-S; Hammermeister et al., 2008), Group Environment Questionnaire (GEQ; Carron et al., 1985; Eys et al., 2007), and Social Identity Questionnaire for Sport (SIQS; Bruner & Benson, 2018). Structural equation modeling was used to assess the relationships between peer servant leadership, cohesion, and social identity. Results revealed that peer servant leadership positively predicted cohesion, and this relationship was fully mediated by social identity. The current study supports the effectiveness of peer servant leadership in sport contexts and provides theoretical support for the social identity approach to leadership.     

Individual postdecision processes in group settings

In two experiments Differentiation and Consolidation Theory (Diff Con) (Svenson, 1992) was used to investigate individual postdecision making processes in three-member groups. It was predicted that in groups in which the subjects preferred different alternatives (conflict groups), subjects would consolidate their own preferred alternative, and not the group's final decision. A second hypothesis was that no consolidation would be indicated in groups in which all members preferred the same alternative (non-conflict groups). The results showed that in conflict groups, the members who gave up their preferred alternative (minority members) consolidated their own preference, thereby significantly regretting the group decision. In contrast, members who got their own will through in the majority decision (majority members) showed no consolidation of the group decision. The corresponding pattern of results was replicated in a second experiment, using a different decision situation. The results indicated that perceptions of social support, agreement in a group and decreasing responsibility for a group's decision, could all partly substitute consolidation by attractiveness restructuring.