Use brainwriting to defeat production blocking

Have everyone write ideas silently at the same time, then share — this is the group brainstorm that research actually supports.

Why it works

Production blocking — only one person can speak at a time in a verbal brainstorm — suppresses output because ideas in working memory decay before they can be voiced. Brainwriting eliminates blocking by letting everyone generate in parallel. The research case for brainwriting over traditional verbal brainstorming is the clearest result in the ideation literature.

How to do it

1. Give everyone paper or a shared document and set a silent generation period (5–10 minutes).
2. Each person writes every idea that comes to mind without speaking or reacting to others.
3. After the silent phase, share all ideas at once, then use the combination rule to build on what’s there.
4. Optional: pass sheets in a circle so each person’s current sheet triggers new ideas (the 6-3-5 method).

Evidence

Multiple controlled experiments find that nominal groups (individual generation then pooling) and brainwriting formats consistently outperform traditional verbal brainstorming on quantity and often quality of ideas. Diehl and Stroebe’s follow-up experiments isolate production blocking — not motivation loss or evaluation apprehension — as the primary cause, which is exactly what parallel writing removes. (rct)

Studies vary in task type and group size; the advantage of brainwriting is most consistent for quantity and is somewhat smaller for originality.

Sources

• Diehl & Stroebe (1987), Productivity loss in brainstorming groups, Journal of Personality and Social Psychology
• Paulus & Yang (2000), Idea generation in groups: a basis for creativity in organizations, Organizational Behavior and Human Decision Processes
• Diehl, M., & Stroebe, W. (1987). Productivity loss in brainstorming groups: Toward the solution of a riddle. Journal of Personality and Social Psychology, 53(3), 497–509.
• Diehl, M., & Stroebe, W. (1991). Productivity loss in idea-generating groups: Tracking down the blocking effect. Journal of Personality and Social Psychology, 61(3), 392–403.
• Paulus, P. B., & Yang, H.-C. (2000). Idea generation in groups: A basis for creativity in organizations. Organizational Behavior and Human Decision Processes, 82(1), 76–87.
• Mullen, B., Johnson, C., & Salas, E. (1991). Productivity loss in brainstorming groups: A meta-analytic integration. Basic and Applied Social Psychology, 12(1), 3–23.

Common mistake

Treating verbal brainstorming as the default and brainwriting as an optional add-on — the evidence reversal is complete enough that brainwriting should usually be the default.