Shared information bias is known as the tendency for group members to spend more time and energy discussing information that all members are already familiar with, and less time and energy discussing information that only some members are aware of. Harmful consequences related to poor decision-making can arise when the group does not have access to unshared information in order to make a well-informed decision.
Causes
Although discussing unshared information may be enlightening, groups are often motivated to discuss shared information in order to reach group consensus on some course of action. According to Postmes, Spears, and Cihangir, when group members are motivated by a desire to reach closure, their bias for discussing shared information is stronger. However, if members are concerned with making the best decision possible, this bias becomes less salient. In support of the observations by Postmes et al., Stewart and Stasser have asserted that the shared information bias is strongest for group members working on ambiguous, judgment-oriented tasks because their goal is to reach consensualagreement than to distinguish a correct solution. The shared information bias may also develop during group discussion in response to the interpersonal and psychological needs of individual group members. For example, some group members tend to seek group support for their own personal opinions. This psychological motivation to garner collective acceptance of one's own initial views has been linked to group preferences for shared information during decision-making activities Lastly, the nature of the discussion between group members reflects whether biases for shared information will surface. According to Wittenbaum et al., 2004), members are motivated to establish and maintain reputations, to secure tighter bonds, and to compete for success against other group members. As a result, individuals tend to be selective when disclosing information to other group members.
Several strategies can be employed to reduce group focus on discussing shared information:
Make effort to spend more time actively discussing collective decisions. Given that group members tend to discuss shared information first, longer meetings increaselikelihood of reviewing unshared information as well.
Make effort to avoid generalized discussions by increasing the diversity of opinions within the group.
Introduce the discussion of a new topic to avoid returning to previously discussed items among members.
Avoid time pressure or time constraints that motivate group members to discuss less information.
Clarify to group members when certain individuals have relevant expertise.
Include more group members who have task-relevant experience.
Technology can also offer group members a way to catalog information that must be discussed. These technological tools help facilitate communication between members while structuralizing the group's decision-making process.