Investigating the effects of co-witness influence on blame attribution.

Through the use of misinformation paradigms, research has demonstrated that eyewitnesses can be influenced by their co-witnesses when attempting to attribute blame to the correct person in incidents where there are multiple potential suspects at blame (such as a fight or car accident). The act of blame conformity could directly contribute to the false conviction of innocent bystanders and should therefore be a central focus for research. Yet very little research has attempted to investigate the moderating factors associated with blame conformity. The present thesis investigated the effects of co-witness influence on eyewitness blame attribution. More specifically, the thesis sought to identify the external and internal predictors of blame conformity. A similar experimental paradigm to Thorley (2015) was created to observe blame conformity. In the present studies, confederates were used to expose participants to misleading post-event information about the witnessed crime footage (suggesting that the wrong person had initiated the assault). Participants were then interviewed and asked if they could determine which person from the incident was to blame for initiating the assault. A series of internal and external variables were measured and manipulated to identify the most accurate predictors of blame conformity. In total, four studies were carried out: The studies investigated the effects of age and gender (study 1a); unanimity and group size of misinformation (study 1b; using same data as 1a); personality characteristics (FIRO-B assessment)(study 2); co-witness familiarity (study 3); and the perceived intelligence and authority of the misinformation source (study 4), on co-witness influence.

The results found no significant age or gender-related differences in blame conformity. In relation to personality; the results suggested eyewitnesses who scored highly on the wanted control dimension were more likely to accept misinformation from cowitnesses, and were more likely to lose confidence in their own judgements after a group discussion. Results also indicated that participants were more vulnerable to co-witness influence when exposed to misinformation from a majority of co witnesses. Misinformation presented by an individual confederate did not have a significant influence on participants’ responses. It was found that the level of statement similarity with regard to blame attribution was higher when the co-witnesses had a pre-existing relationship. Results indicated that participants were also more likely to conform to the confederate if she was presented as having high intelligence, in comparison to a confederate whose personal characteristics were undisclosed. After controlling for perceived intelligence, the perceived authority of the confederate did not have a significant effect on their influence over the participants. The implications and practical applications of the findings — as well as directions for future research— are discussed within the thesis.