This preregistered meta-analysis theoretically and empirically integrates the two research strands on effort gains and effort losses in teams. Theoretically, we built on Shepperd's (1993) framework of productivity loss in groups and Karau and Williams' (1993) Collective Effort model (CEM) and developed the Team member Effort Expenditure model (TEEM), an extended Expectancy × Value framework with the explicit addition of an individual work baseline. Empirically, we included studies that allowed calculating a relevant effect size, which represents the difference between an individual's effort under individual work and under teamwork conditions. Overall, we included 622 effect sizes (N = 320,632). We did not find a main effect of teamwork on effort. As predicted, however, multilevel modeling revealed that the (in-)dispensability of the own contribution to the team performance, social comparison potential, and evaluation potential moderated the effect of teamwork versus individual work on expended effort. Depending specifically on the level of (in-)dispensability and the potential to engage in social comparisons, people showed either effort gains or losses in teams. As predicted, we also found that people's self-reports indicated effort gains when they had objectively shown such gains, whereas their self-reports did not indicate effort losses when they had shown such losses. Contrary to our hypotheses, team formation (i.e., ad hoc vs. not ad hoc teams) and task meaningfulness did not emerge as moderators. Altogether, people showed either effort gains or losses in teams depending on the specific design of teamwork. We discuss implications for future research, theory development, and teamwork design in practice. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

中文翻译：

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一起，每个人都取得或多或少的成就？关于团队努力得失的跨学科元分析。

这种预先注册的元分析在理论上和经验上整合了团队中努力收益和努力损失的两个研究方向。从理论上讲，我们建立在 Shepperd (1993) 的群体生产力损失框架和 Karau 和 Williams (1993) 集体努力模型 (CEM) 的基础上，并开发了团队成员努力支出模型 (TEEM)，这是一个扩展的预期 × 价值框架，具有明确的添加个人工作基线。根据经验，我们纳入了允许计算相关效应量的研究，该效应量代表个人在个人工作和团队合作条件下的努力之间的差异。总的来说，我们包括了 622 个效应量（N = 320,632）。我们没有发现团队合作对努力的主要影响。然而，正如预测的那样，多层次模型显示，自身对团队绩效、社会比较潜力和评估潜力的贡献的（非）可有可无性缓和了团队合作与个人工作对花费努力的影响。具体取决于（非）可有性的水平和参与社会比较的潜力，人们在团队中表现出努力的收益或损失。正如预测的那样，我们还发现，当人们客观地表现出这种收益时，他们的自我报告表明了努力的收益，而当他们表现出这种损失时，他们的自我报告并没有表明努力的损失。与我们的假设相反，团队组建（即临时团队与非临时团队）和任务意义并没有作为调节因素出现。共，根据团队合作的具体设计，人们在团队中表现出努力的收益或损失。我们在实践中讨论对未来研究、理论发展和团队合作设计的影响。（PsycInfo 数据库记录 (c) 2021 APA，保留所有权利）。