When groups of people get together to make decisions, they often struggle to fulfil their potential. Part of the reason is that they tend to spend more time talking about information that everyone shares rather than learning fresh insights from each other. In a forthcoming paper, Andreas Mojzisch and Stefan Schulz-Hardt have uncovered a new reason groups so often make sub-optimal decisions. The researchers show that when a group of people begin a discussion by sharing their initial preferences, they subsequently devote less attention to the information brought to the table by each member, thus leading the group to fail to reach the optimal decision. The practical implications are clear - if you can, avoid beginning group decision-making sessions with the exchange of members' initial preferences.
Mojzisch and Schulz-Hardt began their investigation with a carefully controlled simulation of a real group discussion. Rather than exchanging ideas face-to-face, dozens of participants were presented with some selective written information about various job candidates and either told or not told about the initial preferences of other group members who'd received different information. Each participant then received the information that had been given to all the other group members.
Participants needed to consider the information available to the entire group if they were to identify the optimum candidate. Crucially, participants who began the session by hearing about other group members' initial candidate preferences were subsequently less successful at using the group's shared information to pick the optimum candidate. A memory test suggested this was because they'd paid less attention to the relevant information than had the participants who'd been kept in the dark about other members' initial candidate preferences.
A final study tested these effects in a real, face-to-face group decision-making situation. One hundred and eighty students participated in sixty three-person groups tasked with selecting the best among three job candidates. Each group member started off with a unique set of information about the three candidates and the optimum candidate selection could only be reached if group members shared with each other their unique information. Once again, groups were far less successful at sharing the necessary information, and therefore at reaching an optimal decision, if they began their session by sharing their initial candidate preferences. As before, the reason was that sharing initial preferences led group members to pay less attention to the relevant information during group discussion.
'The take-home-message of our study is simple,' Mojzisch told the Digest. 'Ninety per cent of group discussions start with the members exchanging their pre-discussion preferences. Our research shows that learning the other group members' preferences at the beginning of a group discussion has a negative effect on the quality of group decision-making.'
Andreas Mojzisch, & Stefan Schulz-Hardt (2010). Knowing others' preferences degrades the quality of group decisions. Journal of Personality and Social Psychology.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
PS. The authors of the current study tipped off the Digest editor about their research findings. If you have some exciting peer-reviewed research in press, you too could tip off the Digest editor, for the chance to have your findings popularised on one of the world's leading psychology blogs. Email: christianjarrett[@]gmail.com Thanks!