Investigating the effects co-witness familiarity on statement similarity

The present study examined the effects of a co-witness familiarity on statement similarity. The study aimed to identify whether eyewitnesses were at a higher risk of conforming to co-witnesses that they were familiar with, than to unfamiliar co-witnesses. The study utilised a novel experimental paradigm in which participants viewed footage of a crime before partaking in a post-event discussion with their group. It employed a one-way between subjects design, where participants either had a pre-existing relationship with their co-witnesses, had no previous relations to their co-witnesses, or were not permitted to discuss the event with their co-witnesses (control). Four hundred twenty participants took part in the study. They were placed into groups of five and viewed a CCTV footage of bar fight breaking out, due to the ambiguity of the footage, there was a clear heterogeneity of statements. Participants then took part in a post-event discussion with group members before giving individual statements. A one-way between groups analysis of variance (ANOVA) was conducted. Results indicated that a post-event discussion significantly increased the level of statement similarity with eyewitness groups, but only when the co-witnesses shared a pre-existing relationship. The results also indicated that uncertain eyewitnesses were most susceptible to co-witness influence. The results indicate that eyewitnesses are more likely to accept contradicting information from peers than from strangers. Explanations for the findings, along with implication for police interventions, are discussed.