1. Poor facilitation
2. Wrong (or poorly articulated) topic
3. Unmotivated participants
4. Insufficient diversity of participants
5. No transition from “business as usual”
6. Inadequate orientation
7. Lack of clear ground rules
8. Sterile meeting space
9. Hidden (or competing) agendas
10. Lack of robust participation
11. Insufficient listening
12. Habitual idea killing behavior
13. Attachment to old (“pet”) ideas
14. Discomfort with ambiguity
15. Hyper-seriousness (not enough fun)
16. Endless interruptions
17. PDA addiction (Crackberries)
18. Impatience (premature adoption of the first “right idea”)
19. Group think
20. Hierarchy and/or competing sub-groups
21. Imbalance of divergent and convergent thinking
22. No tools and techniques to spark the imagination
23. Inelegant ways of capturing new ideas
24. No time for personal reflection
25. Pre-mature evaluation
26. No follow-up plan
Source