Eyewitness memory distortion following co-witness discussion: a replication of Garry, French, Kinzett, and Mori (2008) in ten countries

We examined the replicability of the co-witness suggestibility effect originally reported by Garry et al. (2008) by testing participants from 10 countries (Brazil, Canada, Colombia, India, Japan, Malaysia, Poland, Portugal, Turkey, and the United Kingdom; total N=486). Pairs of participants sat beside each other, viewing different versions of the same movie while believing that they viewed the same version. Later, participant pairs answered questions collaboratively, which guided them to discuss conflicting details. Finally, participants took a recognition test individually. Each of the 10 samples replicated the Garry et al. finding: Participants often reported on the final test a non-witnessed answer that their co-witness had stated during the collaboration phase. Such co-witness suggestibility errors were especially likely when the witness had not disputed the co-witness's report during the collaboration phase. The results demonstrate the replicability and generalizability of the co-witness suggestibility effect.
This research was supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (KAKENHI No. 25280050) to Kazuo Mori and a grant from Aichi University (KENKYUJOSEI No. C-180) to Hiroshi Ito. Kazuo Mori was also supported by the Joint Research Grant 2017 from the Promotion and Mutual Aid Corporation for Private Schools of Japan to Matsumoto University for cooperative research with Aichi University. While conducting the study and writing of the manuscript, Krystian Barzykowski was supported by a grant from the National Science Centre, Poland [No.: 2015/19/D/HS6/00641]. Nicole Laird's work on this project was supported by a Natural Science and Engineering Research Council Discovery Grant to D. Stephen Lindsay.