Shared information bias refers to the tendency for groups to spend more time discussing information that all members know (shared information) and less time examining information that only a few members know (unshared).
Shared information bias is a phenomenon in which groups tend to focus on information that is already known to most group members and overlook unique information that is held by only a few individuals. This bias occurs because group members tend to be more confident in and feel more comfortable discussing information that they believe is shared by everyone in the group.
For example, a group of coworkers may be tasked with developing a new project, and during a brainstorming session, they may spend a lot of time discussing ideas that are already familiar to everyone in the group, rather than considering new and unique perspectives brought by a few members.
Another example of shared information bias could be a jury discussing a case. The members may tend to focus on information that is already presented in court documents, rather than unique information presented by individual jurors that could lead to a different verdict.
Shared information bias can lead to poor decision-making and missed opportunities for finding creative solutions to problems. To combat this bias, group leaders can encourage members to share their unique perspectives and information, and can assign someone to explicitly seek out and present such information to the group.