── ── Mental model
Six Thinking Hats
Six Thinking Hats (Edward de Bono, 1985) prevents the most common meeting failure: different thinking modes colliding simultaneously. The fix is parallel thinking — everyone uses the same mode at the same time. Six hats: White (data/facts), Red (gut/emotions), Black (caution/risk), Yellow (optimism/value), Green (creativity/alternatives), Blue (process/meta).
How it works
Six phases → Six Hats Analysis. Stop rule: if Blue Hat close reveals no dominant direction, identify the most contested hat phase and schedule a focused session on it alone rather than forcing a decision.
1. Blue Hat opens (5 min): Define the question, hat sequence, time limits, and rules (no switching modes during a hat phase). 2. White Hat — facts and data (10 min): State known facts only. Distinguish confirmed data from soft data. List information gaps explicitly. 3. Yellow Hat — optimism and value (8 min): Generate specific benefits with logical basis. Run before Black to prevent habitual pessimism dominating. 4. Black Hat — caution and risk (10 min): Identify specific, evidence-based risks. "I don't like it" is Red Hat. "The API will fail under rate limits because X" is Black Hat. Do not abbreviate. 5. Green Hat — creativity and alternatives (8 min): Generate alternatives — no evaluation. Facilitator must actively block Black Hat intrusions. 6. Red Hat — gut feeling (2 min, 30 sec per person): One sentence per person, no justification required or permitted. 7. Blue Hat closes (5 min): Synthesize decision, action items, most critical Black Hat risk, most promising Green Hat direction.
When to use it
- group decision degenerates into debate
- proposal needs multi-angle evaluation
- creative ideas get killed by habitual criticism
- someone says "let's look at this from all angles," "we keep going in circles," "we need structure"*
- individual high-stakes decision needs forced multi-angle review
When not to use it
the question has a clear empirical answer (use critical-thinking instead), or time is under 10 minutes and no setup is possible.
Worked example
ABB Global Management Meetings (1990s)
A primary-source-documented case. Percy Barnevik, CEO of ABB (the Swedish-Swiss engineering conglomerate) from 1988 to 1996, documented the adoption of the Six Hats method in ABB's management structure in interviews and in de Bono's subsequent documentation of the case.
Install this skill (free, MIT)
npx skills add deciqAI/knowledge-skills