Mutual enhancement: Toward an understanding of the collective preference for shared information.

Groups tend to discuss and repeat information known by all members (shared) more than they do information known by one member (unshared). One factor that may influence this effect is the tendency for members to positively evaluate one another when mentioning shared information. Three experiments demonstrated this mutual enhancement effect. Experiment I showed that mutual enhancement was related to participants' and their partners' exchanging the same pieces of information. Experiment 2 illustrated that mutual enhancement was not related to the extent that participants liked partners or saw them as having similar opinions. Experiment 3 showed mutual enhancement in face-to-face dyads that discussed shared information. A combined analysis across the 3 experiments showed the robustness of mutual enhancement. Implications of mutual enhancement for group discussion are considered.