Group membership and eyewitness testimony

Abstract: The present thesis includes four empirical studies that explore whether eyewitness accounts of a violent crime may be affected by factors related to the group membership of witness, perpetrator, and victim.Study 1 investigates how an immigrant and a Swedish perpetrator of a simulated, violent robbery are evaluated and remembered by immigrant and Swedish witnesses. It was found that both groups of witnesses evaluated an ethnically dissimilar, out-group perpetrator as more culpable than an ethnically similar, in-group perpetrator. In a line-up task, both witness groups mistakenly identified an innocent immigrant more often than an innocent Swede. Study 2 compared experienced police officers and civilians with respect to intergroup biases and memory performance in a witness situation. The results showed that the police officers were less ethnocentric than the civilians in their evaluations of an immigrant and a Swedish perpetrator. Moreover, the police officers remembered the perpetrator and his weapon more accurately than the civilians. In Study 3, the influence of the gender of witness, perpetrator, and victim on an eyewitness report was examined. This study showed that women were more accurate than men in overall memory of a simulated mansslaughter incident involving either a male or a female perpetrator and a male or a female victim. Furthermore, both a male perpetrator and a male victim were assigned more culpability than their female counterparts. Study 4 explores the effects of stereotype priming in an eyewitness context. The results indicated that the priming of a social stereotype may have an impact on eyewitness evaluations and memories of a violent perpetrator who is not a member of the target group.In sum, the findings of the four studies clearly supported the contention that the group membership of both witness and target persons in a crime scenario can have a significant impact on eyewitness testimony. These results suggest that potential effects of group membership should be thoroughly considered when testimony is evaluated in court proceedings.