Groups spend their discussion on information everybody already holds and neglect information held by only one member, which is the information the group needed.
Stasser and Titus showed in 1985 that shared items are more likely to be mentioned, more likely to be repeated, and more likely to be treated as valid, simply because more people can introduce and confirm them. The result is that discussion tends to pool what was already common and leave the decisive fragment with the one person who had it.
In practice
- A hiring panel spends forty minutes on the CV everyone read and two on the reference only one member saw.
- A review meeting reaches confident agreement on the things that needed no meeting.
- Standing
- The hidden-profile paradigm is the experimental setup that demonstrates it.
- Further reading
- Wikipedia
- Subject
- Decision-making & Reasoning
- Essay
- The catalogue of predictable errors