The Hidden Profile Effect
When the best option only shows up once everyone's unique knowledge is pooled, groups usually miss it. Discussion keeps returning to what everyone already knows.
The hidden profile effect is how a group holding every fact it needs still picks the wrong option. The facts are spread across people, and the discussion never puts them together.
In 1985, Garold Stasser and William Titus had groups of four university students choose a student body president from three candidates. One candidate was clearly strongest: eight positive traits against four for each rival. When everyone read the full profiles, 83% of groups chose that candidate. When the strengths were split so each person held only a few, 18% did.
Nobody was hiding anything. A fact four people hold has four chances to come up. A fact one person holds has one. So discussion circles what everyone already knows.
A 2012 meta-analysis of 65 studies and 3,189 groups found that groups facing a hidden profile were eight times less likely to find the best answer. Meeting online rather than in person made no difference.
The nudge: Before your next decision meeting, ask each person to send you, in writing, one fact about the options they suspect others don't have. Read them all out before anyone states a preference.
Source: Stasser & Titus, Pooling of unshared information in group decision making: Biased information sampling during discussion, Journal of Personality and Social Psychology (1985); Lu, Yuan & McLeod, Twenty-five years of hidden profiles in group decision making: A meta-analysis, Personality and Social Psychology Review (2012)
