Together, everyone achieves more-or, less? An interdisciplinary meta-analysis on effort gains and losses in teams.

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).