Investigating the Effects of Pre-existing Co-Witness Relationships on Statement Similarity.

Objectives:
The present study examined the effects of a pre-existing relationship between co-witnesses on memory conformity. 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.
Design:
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 three-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).
Methods:
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.
Results:
A one-way between groups analysis of variance (ANOVA) was conducted. Results indicated that eyewitness groups with pre-existing relationships had a significantly higher level of statement similarity than eyewitnesses in the control and no-relations conditions. There were no significant differences in statement similarity between eyewitnesses who discussed the event with strangers and eyewitnesses in the control groups.
Conclusions:
The results indicate that eyewitnesses are more likely to accept misinformation from peers than from strangers. Explanations for the findings, along with implication for police interventions, are discussed.