The effects of interrogative pressure in simulated forensic interviews

• Main Author: McGroarty, Allan
• Published: University of Strathclyde 2007
• Subjects: 158.39
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501700

The purpose of this thesis was to investigate the effects of interrogative pressure on interviewee behaviour, particularly the tendency to change previous answers during requestioning. The three main studies used an experimental procedure adapted from the Gudjonsson Suggestibility Scales (GSS; Gudjonsson, 1984,1987b). Two amendments were made to the standard GSS procedure to increase ecological validity: questions asked of participants were nmnimally rather than overtly leading and were applied to a video presentation of a simulated crime as opposed to a narrative passage. The repeated questions and negative feedback aspects of the GSS procedure were retained. Study 1 examined the effects of two types of feedback and the presence of a second interviewer. Compared with neutral feedback, negative feedback resulted in more response changes, higher state anxiety and higher ratings of interview difficulty. The results also suggest that the presence of a second interviewer, at least one who has a minimal involvement in questioning, is not likely to influence the recall of interviewees. Study 2 investigated the influence on interviewee behaviour of an intervention made by a supportive "ally". A warning communicated by the ally immediately following feedback was found not to reduce response change. Study 3 examined the effects of two types of interviewer behaviour. An abrupt manner during questioning, compared to a friendly manner, resulted in more response changes. Studies 2 and 3 also assessed the influence of levels of interviewee self-esteem on interviewee responding. Low levels of self-esteem were found to be associated with increased self-reported anxiety following questioning and rated difficulty of the interview, but not with increased response change. These findings indicate that, if not carefully monitored and controlled, critical forms of verbal feedback and negative demeanour of interviewers can operate as suggestive influences which may compromise the reliability of testimony.