Why collaboration reduces suggestibility: the role of source-monitoring processes and retrieval strategies

Previous research found that collaboration reduces the tendency to yield to misleading questions. Here, the aim was to determine whether this occurs because collaboration induces a conservative change in response criterion or because it promotes more efficient error-checking strategies. To this purpose, we compared the performance of collaborative and nominal triads in the Gudjonsson Suggestibility Scale. Critically, we recorded conversations during retrieval, allowing us to compute inclusive scores and analyze retrieval strategies. Confirming previous evidence, results showed that collaborative groups yielded less to leading questions; however, the differences between collaborative and nominal groups in yield 1 were canceled when we took into account questions to which at least one participant in the collaborative group gave in but was corrected by collaborators during the discussion (the so-called inclusive scores). This was not the case for yield 2 and total suggestibility scores. Also, the analysis of retrieval strategies indicated that collaborative groups who used process-focused strategies (such as correction and cross-cueing) to a greater extent were less likely to change their responses after receiving the negative feedback and were less suggestible. We conclude that, while the use of error-checking and process-focused strategies played a role in reducing suggestibility in collaborative groups, the administration of negative feedback induced members of collaborative groups to adopt a more conservative response criterion. These results contribute to the understanding of the conditions that maximize the positive effects of collaborative retrieval. They have implications for policymakers and police practitioners, specifying when and how collaboration might be allowed.