Tuesday, April 10, 2012

When two heads are worse than one - the cost of collaboration

An interesting bit in Psychological Science from Minson and Mueller, who demonstrate that joint decision making exacerbates rejection of outside information and lowers accuracy of the effort:
Prior investigators have asserted that certain group characteristics cause group members to disregard outside information and that this behavior leads to diminished performance. We demonstrate that the very process of making a judgment collaboratively rather than individually also contributes to such myopic underweighting of external viewpoints. Dyad members exposed to numerical judgments made by peers gave significantly less weight to those judgments than did individuals working alone. This difference in willingness to use peer input was mediated by the greater confidence that the dyad members reported in the accuracy of their own estimates. Furthermore, dyads were no better at judging the relative accuracy of their own estimates and the advisor’s estimates than individuals were. Our analyses demonstrate that, relative to individuals, dyads suffered an accuracy cost. Specifically, if dyad members had given as much weight to peer input as individuals working alone did, then their revised estimates would have been significantly more accurate.


  1. Hello Deric -- I'm preparing a talk on group think and I (think it was here) remember reading about a study where people were given group tasks to which there was a 'right' answer, and inevitably, the loudest or most assertive person's suggested course of action was followed, regardless of the correctness of that suggestion ... do you recall anything of that ilk? Keep up the great work :)


  2. Don't have that at my fingertips. I also remember the point, but right now don't have the time to try to dig it up. Sorry.