title: Group heterogeneity increases the risks of large group size: a longitudinal study of productivity in research groups.
abstract: Heterogeneous groups are valuable, but differences among members can weaken group identification. Weak group identification may be especially problematic in larger groups, which, in contrast with smaller groups, require more attention to motivating members and coordinating their tasks. We hypothesized that as groups increase in size, productivity would decrease with greater heterogeneity. We studied the longitudinal productivity of 549 research groups varying in disciplinary heterogeneity, institutional heterogeneity, and size. We examined their publication and citation productivity before their projects started and 5 to 9 years later. Larger groups were more productive than smaller groups, but their marginal productivity declined as their heterogeneity increased, either because their members belonged to more disciplines or to more institutions. These results provide evidence that group heterogeneity moderates the effects of group size, and they suggest that desirable diversity in groups may be better leveraged in smaller, more cohesive units.
authors.affiliation: Fuqua School of Business, Duke University, USA.
authors.forename: Jonathon N
authors.initials: JN
authors.lastname: Cummings
authors.forename: Sara
authors.initials: S
authors.lastname: Kiesler
authors.forename: Reza
authors.initials: R
authors.lastname: Bosagh Zadeh
authors.forename: Aruna D
authors.initials: AD
authors.lastname: Balakrishnan
mesh_terms: D000328:Adult; D015706:Bibliometrics; D004526:Efficiency; D006127:Group Structure; D006801:Humans; D008137:Longitudinal Studies; D012106:Research / Q000458:organization & administration*; D012933:Social Identification; D014481:United States
keywords: performance; social interaction; social structure