Psychology and Crime News

A few new articles on eyewitnessing that caught my eye (natch) recently:

Daniel Wright in the October 2007 issue of Memory ponders the impact of eyewitness identifications from simultaneous and sequential lineups:

< P> Recent guidelines in the US allow either simultaneous or sequential lineups to be used for eyewitness identification. This paper investigates how potential jurors weight the probative value of the different outcomes from both of these types of lineups…[Participants] had to judge the guilt of the suspect and decide whether to render a guilty verdict. For both simultaneous and sequential lineups an identification had a large effect, increasing the probability of a guilty verdict. There were no reliable effects detected between making no identification and identifying a filler… These findings are important for judges and other legal professionals to know for trials involving lineup identifications.

• Wright, D.B. (2007)The impact of eyewitness identifications from simultaneous and sequential lineups. Memory 15(7):746-754

Also in the October 2007 issue of Memory, Timothy J. Perfect, Ian Dennis and Amelia Snell from Plymouth University (UK) report on the effects of local and global processing orientation on eyewitness identification performance:

Recent work has demonstrated that performance on a simultaneous target-present photographic line-up can be enhanced by prior global processing orientation, and hindered by prior local processing orientation induced by processing Navon letter stimuli. A series of studies explore the generality of this processing bias effect using either videotaped scenarios or live interactions. Five experiments demonstrate that these effects are seen across a range of test stimuli, test formats, and test instructions. These data inform the processes engaged in by witnesses when making line-up identifications and indicate that it may be possible to improve the accuracy of witnesses making such judgements.

• Perfect, T.J., Dennis, I. & Snell, A. (2007) The effects of local and global processing orientation on eyewitness identification performance. Memory 15(7):784-798

Finally, in press in Acta Psychologica, James Ost and colleagues report on the effects of confederate influence and confidence on the accuracy of crime judgements. Acta Psychologica

Building on recent work which has investigated social influences on memory and remembering, the present experiment examined the effects of social pressure and confederate confidence on the accuracy and confidence of eyewitnesses. Sixty undergraduate participants watched a video of a staged mugging and then answered questions about the video out loud in the presence of either one or three confederates who had also watched the film with them. Unbeknownst to the participant, the confederate(s) always gave incorrect responses to four out of the eight questions. Participants and confederates were also asked to give confidence scores out loud for each of their answers. Again, unbeknownst to the participant, the confederate(s) always expressed either high or low confidence scores for the incorrect information, depending on condition. Participants gave fewer correct answers, and were less confident, in the presence of three, as opposed to one, confederates. Participants were also more confident, yet no more accurate, when the confederate(s) gave high, as opposed to low, confidence scores. Thus the presumed independence of evidence given by multiple witnesses cannot be safely assumed.

• Ost, J., Ghonouie, H., Cook, L. & Vrij, A. (in press). The effects of confederate influence and confidence on the accuracy of crime judgements . Acta Psychologica

Photo credit: Martin Deutsch, Creative Commons License