Social identity and socially shared retrieval-induced forgetting: The effects of group membership.

In a conversation, speakers and listeners will often influence each other's memories, and in doing so, promote the formation of a shared, or collective, memory. One means by which a mnemonic consensus emerges is through socially shared retrieval-induced forgetting (SSRIF). When listeners attend to the speakers' selective retrieval of previously encountered events, they forget unmentioned but related information more than they forget unrelated, unmentioned previously studied information. As a consequence, both speaker and listeners come to remember-and forget-the event in a similar way. SSRIF appears to be dependent on listeners concurrently retrieving the information with the speaker. We asked here whether such concurrent retrieval is a function of group membership, thereby underscoring the connection between a basic mnemonic mechanism-retrieval-induced forgetting-and a social function of communicative interaction-building a shared representation. In Experiment 1, Princeton students listening to a speaker selectively recall previously studied material showed SSRIF when the speaker was identified as a fellow Princeton student, but not when he or she was identified as a Yale student. In Experiment 2, activating a common student identity before the listening task triggered concurrent retrieval in Princeton students when listening to both Princeton and Yale speakers. Thus, similar patterns of selective forgetting are more likely to occur between speakers and listeners if they belong to the same social group. Basic mnemonic mechanisms seem to be adapted to promote the emergence of shared mnemonic representations that preserve group membership and group identity.