Dara Mojtahedi

Personality Correlates of Co-Witness Suggestibility

ABSTRACT The present study examined the relationship between co-witness suggestibility and individual differences in interpersonal characteristics. Participants (N = 473) took part in an eyewitness simulation, and five independent conditions were used to control for misinformation size. Using confederates, the researchers exposed participants to misinformation about the witnessed event, prior to collecting their statements. The participants then completed the Fundamental Interpersonal Relations Orientation-Behavior assessment (FIRO-B; Schutz, 1958), a measure of expressed and wanted control, affection, and inclusion. Results suggested that the wanted-control dimension was an accurate predictor of co-witness suggestibility. Eyewitnesses who scored highly on wanted control were significantly more likely to accept misinformation from co-witnesses, and were more likely to lose confidence in their own judgments, after a group discussion. In addition, the results suggest that the unanimity of misinformation, but not the size, had a significant influence on co-witness suggestibility.

The Missing Link in Training to Detect Deception and its Implications for Justice

Purpose The purpose of this paper is to investigate the effect of response bias and target gender on detecting deception. Design/methodology/approach Participants were randomly assigned to one of three experimental conditions: a stereotype condition (bogus training group), a tell-signs condition (empirically tested cues), and a control condition. Participants were required to decide whether eight targets were lying or telling the truth, based upon the information they had been given. Accuracy was measured via a correct or incorrect response to the stimuli. The data were then analyzed using a 2×2×3 mixed analysis of variance (ANOVA) to determine whether any main or interactional effects were present. Findings Results revealed training condition had no significant effect on accuracy, nor was there a within-subject effect of gender. However, there was a significant main effect of accuracy in detecting truth or lies, and a significant interaction between target gender and detecting truth or lies. Research limitations/implications Future research should seek a larger sample of participants with a more extensive training aspect developed into the study, as the brief training offered here may not be fully reflective of the extent and intensity of training which could be offered to professionals. Originality/value Within the criminal justice system, the need for increased accuracy in detecting deception is of critical importance; not only to detect whether a guilty individual is being deceitful, but also whether someone is making a false confession, both to improve community safety by detaining the correct perpetrator for the crime but also to maintain public trust in the justice system. The present research provides a fresh insight into the importance of training effects in detecting deception.

A preliminary investigation on the performance of brain-injured witnesses on target-absent line-up procedures

Abstract The current study was a preliminary investigation that aimed to compare the performance of eyewitnesses with and without a brain injury on two target-absent line-up procedures: a simultaneous procedure and a sequential procedure with confidence ratings. A 2 × 2 design (N = 25) was employed, where both brain-injured (n = 15) and non-brain-injured (n = 10) participants were shown a short video of a non-violent crime taking place before taking part in either a simultaneous or sequential target-absent line-up. Participants’ general cognitive abilities and memory recall accuracy were also measured. Results found no significant differences in false identification rates between brain-injured and non-brain-injured witnesses. It was also found that participants with a greater memory accuracy were in fact more likely to make a false identification. The implications and limitations of the study are discussed.

Group size, misinformation and unanimity influences on co-witness judgements

ABSTRACT Researchers have typically observed the effects of co-witness influence on eyewitness pairs. However, research suggests that individuals are more likely to witness crimes in larger groups. Additionally, there is an abundance of evidence suggesting that social influence is heavily moderated by group size. Therefore, the present study aimed to gain a more accurate understanding of the risks of co-witness influence in relation to unanimity and group size effects. Participants (N = 608) viewed and discussed a CCTV footage of a fight breaking out, with co-witnesses, before giving individual statements, where they were asked to identify which person had started the fight; confederates were used to suggest that the wrong man had started the fight. Results indicated that participants were vulnerable to co-witness influence, but only when exposed to misinformation from a majority of co-witnesses. Misinformation presented by an individual confederate did not have a significant influence over the participants’ responses. This study was the first to investigate the effects of group size on blame attribution. The findings suggest that the true risks of co-witness influence may not be as high as originally predicted from research on eyewitness pairs.