Social interactions can simultaneously enhance and distort memories: Evidence from a collaborative recognition task.

Social interactions can strengthen memories, but they can also contaminate them, for instance, when individuals integrate misinformation from social sources into their own memories. In two experiments, we examined such social contagion in a novel recognition-based collaboration task. Groups of three subjects studied lists of words in isolation, but unbeknownst to subjects, only half of these words were shared by the whole group. The remaining words were shared by two individuals within the group, or they were unshared, studied by single individuals only. Subjects completed a first recognition test collaboratively, and we examined how this group recognition task affected subsequent individual recognition, both for originally studied and unstudied items. Moreover, for some subjects an initial individual test was placed before collaboration, to examine if prior individual retrieval influences social contagion. Three main findings emerged: First, collaboration enhanced individual memory for initially studied information, but mostly for information shared within the group. Second, collaboration entailed robust social contagion effects, which were more pronounced when the misinformation was shared by both other group members. Third, an individual memory test before collaboration reduced social contagion. We discuss the powerful effects of memory retrieval and how social interactions can simultaneously enhance and distort memories.