The productivity gap
Researchers compare real groups with nominal groups, whose members work alone and have their non-duplicate ideas pooled. Beginning with Taylor, Berry, and Block in 1958, and summarized by Mullen and colleagues in a 1991 meta-analysis, nominal groups usually come out ahead on the number of ideas, and often on judged quality too. People nonetheless tend to believe group sessions are more productive.
Why groups lose ideas
Several explanations have been tested. Diehl and Stroebe's experiments pointed especially to production blocking.
- Production blocking: only one person can speak at a time, so ideas are forgotten or suppressed while waiting
- Evaluation apprehension: people hold back ideas for fear of judgment
- Social loafing: individual effort falls when contributions are pooled
- Convergence: members drift toward similar ideas and a shared standard
When collaboration helps
The conclusion is not that teams are useless for creative work. Idea quantity in a short session is a narrow measure, and groups may do better at selecting and developing ideas or combining diverse knowledge. Written or electronic brainstorming, in which people can contribute at the same time, reduces blocking and can match or exceed nominal groups under some conditions. Alternating individual and group phases is a common recommendation.
Further reading
- Taylor, D. W., Berry, P. C., & Block, C. H. (1958). Does group participation when using brainstorming facilitate or inhibit creative thinking? Administrative Science Quarterly, 3(1).
- Diehl, M., & Stroebe, W. (1987). Productivity loss in brainstorming groups: Toward the solution of a riddle. Journal of Personality and Social Psychology, 53(3).
- Mullen, B., Johnson, C., & Salas, E. (1991). Productivity loss in brainstorming groups: A meta-analytic integration. Basic and Applied Social Psychology, 12(1).