Collective memories are shared representations of a group’s past based on a common identity. Social psychological approaches of collective memory have addressed their antecedents and functions. Their formation is affected by cognitive and emotional factors, but it takes place in the context of human interactions with other humans or with cultural artifacts. They are shaped by, and transmitted through, narratives. Because they intervene in the definition, maintenance, and mobilization of social identities, they have a strong impact on intergroup relations. Collective memories influence the present, but they are also influenced by present psychological states and needs.