Lineup administrator influences on eyewitness identification and eyewitness confidence

Lineup administrators were trained to respond to witnesses in such a way as to redirect them from making non-identifications or foil identification responses toward making identifications of the suspect. Compared to a no-influence control condition, suspect identification rates in the influence condition increased substantially and proportionally for guilty and innocent suspects. Administrators steered witnesses more specifically toward the suspect when the suspect was guilty than when the suspect was innocent. Post-identification confidence for correct identifications of the guilty suspect did not differ significantly across the influence and no-influence groups. However, post-identification confidence for false identifications of the innocent suspect was significantly lower for the influence group than for the no-influence group because witnesses who were influenced to make false identifications tended to be those who were less confident prior to the lineup, and also because those witnesses became less confident from pre- to post-identification.     

Confidence and accuracy of lineup selections and rejections: Postdicting rejection accuracy with confidence

Correlation and calibration approaches show meaningful, positive confidence-accuracy relations for witnesses making selections from lineups, but rarely for rejections (Brewer and Wells, 2006, Sauerland and Sporer, 2009). This disparity may reflect the difference between selecting a single photo versus rejecting a set of photos. Participants (N = 101) in two experiments made selections from and rejections of lineups in situations requiring either a single confidence rating about a single face (typical of “choosers”) or a single confidence rating about multiple faces (typical of “nonchoosers”). Mean confidence ratings were significantly higher for accurate versus inaccurate decisions for both selections and rejections when decisions were based on single faces. Single decisions about multiple faces produced no significant difference in confidence between correct and incorrect rejections but a significant difference for selections.     

The effect of biased lineup instructions on eyewitness identification confidence

Although it is well‐known that biased lineup instructions (i.e., those that do not inform witnesses the perpetrator may not be in the lineup) inflate false identifications, their effects on witness confidence are less well understood due to methodological limitations of past studies. We report two studies that use novel methodologies to obviate these limitations. Study 1 (N = 177) demonstrated that biased lineup instructions increased witnesses' average estimates of the likelihood that a lineup member is guilty. Study 2 (N = 137) introduces a novel debiasing paradigm that allows a parsing of choosers into those who made an identification only because of the biased instructions (induced choosers), and those who would have chosen despite the instructions (inherent choosers). Biased lineup instructions inflated confidence only among induced choosers, but not among inherent choosers. Contrary to legal reasoning, witness confidence is an insufficient metric to determine the suggestiveness of biased instructions.     

The influence of alcohol and weapon presence on eyewitness memory and confidence

In this quasi-experimental field study, bar drinkers (0.00–0.23% blood alcohol content) viewed a photographic sequence in which a male took a laptop from a helpdesk assistant, either on loan or at gunpoint. Following a brief retention period, participants answered 20 multiple-choice questions about the male, his actions, and details of the scene, then attempted to identify him from a simultaneous target-present or target-absent line-up. Alcohol was associated with a reduction in correct identifications and an increase in false identifications. Surprisingly, the presence of a weapon in the scene enhanced identification accuracy, though wider scene memory was not influenced by alcohol or the weapon. Findings offer some support for the view that alcohol restricts face encoding, perhaps through the narrowing of attention to salient external features (e.g., hair). We also suggest that curiosity about mock-crime perpetrators may produce weapon focus reversals, although the factors that might elicit such curiosity remain unclear.     

Exposure duration: Effects on eyewitness accuracy and confidence

The current study examined the relationship between the length of exposure to a face in an eyewitness setting and identification accuracy and confidence. A sample of 164 young (ages 17–25) and older (ages 59–81) adults viewed a simulated crime in which they saw the culprit's face for a short (12 s) or long (45 s) duration. They were then tested with a target absent (a line‐up not containing the culprit) or target present line‐up. Identification accuracy rates for both young and older participants were significantly higher under the long exposure condition. In the short exposure condition, witnesses who had made a correct identification of the target were more confident than incorrect witnesses. In the long exposure condition the confidence ratings of accurate and inaccurate witnesses did not differ. Discussion focuses on the extent to which extended exposure may inflate confidence judgments and variables that may moderate the relationship between exposure duration and face recognition accuracy.     

Mood effects on eyewitness memory: Affective influences on susceptibility to misinformation

Does mood influence the accuracy of eyewitness recollections, and people’s susceptibility to misleading information in particular? Based on recent affect-cognition theories and research on eyewitness memory, three experiments predicted and found that positive affect promoted, and negative affect inhibited the incorporation of misleading information into eyewitness memories. This effect was obtained for both positive and negative events (Experiment 1), and for recorded as well as real-life incidents (Experiment 2). Participants had no meta-cognitive awareness of these mood effects, and affect-control instructions were ineffective in preventing them (Experiment 3). The cognitive mechanisms responsible for mood effects on eyewitness memories are discussed, and the implications of these findings for everyday memories, forensic practice and for current affect/cognition theorizing are considered.     

The effects of confederate influence and confidence on the accuracy of crime judgements

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.     

How to protect eyewitness memory against the misinformation effect: A meta-analysis of post-warning studies

Four decades of research and hundreds of studies speak to the power of post-event misinformation to bias eyewitness accounts of events (see e.g., Loftus’ summary, 2005). A subset of this research has explored if the adverse influence of misinformation on remembering can be undone or at least reduced through a later warning about its presence. We meta-analyzed 25 such post-warning studies (including 155 effect sizes) to determine the effectiveness of different types of warnings and to explore moderator effects. Key findings were that (1) post-warnings are surprisingly effective, reducing the misinformation effect to less than half of its size on average. (2) Some types of post-warning (following a theoretical classification) seem to be more effective than others, particularly studies using an enlightenment procedure (Blank, 1998). (3) The post-warning reduction in the misinformation effect reflects a specific increase in misled performance (relative to no warning), at negligible cost for control performance. We conclude with a discussion of theoretical and practical implications.     

Children's metacognitive judgments in an eyewitness identification task

Two experiments examined children's metacognitive monitoring of recognition judgments within an eyewitness identification paradigm. A confidence-accuracy (CA) calibration approach was used to examine patterns of calibration, over-/underconfidence, and resolution. In Experiment 1, children (n=619, mean age=11 years 10 months) and adults (n=600) viewed a simulated crime and attempted two separate identifications from 8-person target-present or target-absent lineups given lineup instructions that manipulated witnesses choosing patterns by varying the degree of social pressure. For choosers, but not nonchoosers, meaningful CA relations were observed for adults but not for children. Experiment 2 tested a guided hypothesis disconfirmation manipulation designed to improve the realism of children's metacognitive judgments. Children (N=796, mean age=11 years 11 months) in experimental and control conditions viewed a crime and attempted two separate identifications. The manipulation had minimal impact on the CA relation for choosers and nonchoosers. In contrast to adults, children's identification confidence provides no useful guide for investigators about the likely guilt or innocence of a suspect. These experiments revealed limitations in children's metacognitive monitoring processes that have not been apparent in previous research on recall and recognition with younger children.     

ROC analyses in eyewitness identification research

There has been a recent surge of interest in analyzing the results of eyewitness identification experiments using Receiver Operating Characteristic (ROC) curves. Proponents of this approach have argued not only that ROC analyses are useful but that more traditional approaches are deficient and should not be used. Three arguments might be made for why researchers would prefer ROC approaches over other techniques. The first is that ROC analyses can provide an index of underlying memory discriminability. The second is that ROC analyses provide useful information about the practical utility of identification procedures. The third is that ROC analyses are useful for testing theory. In this article, I critically examine each of these arguments and conclude that recent claims that ROC methods provide the only justifiable method of comparing identification procedures are overstated.     

The effects of co-witness discussion on confidence and precision in eyewitness memory reports

We examined the influence of co-witness discussion on the metacognitive regulation of memory reports. Participants (N?=?92) watched a crime video. Later, a confederate confidently agreed with (gave confirming feedback), disagreed with (gave disconfirming feedback), or gave no feedback (control) regarding participants’ answers to questions about the video. Participants who received disconfirming feedback reported fewer fine-grain details than participants in the confirming and control conditions on a subsequent, individual recall test for a different question set. Unexpectedly, this decrease in fine-grain reporting was not accompanied by a decrease in participants’ confidence in the accuracy of their fine-grain responses. These results indicate that receiving social comparative feedback about one’s memory performance can affect rememberers’ metamemorial control decisions, and potentially decrease the level of detail they volunteer in later memory reports. Further research is needed to assess whether these results replicate under different experimental conditions, and to explore the effects of social influences on metamemory.     

Some experimental influences of lawyers' complicated questions on eyewitness confidence and accuracy

Eyewitness evidence and the confidence the eyewitness expresses in such evidence are crucial in many criminal trials. The present study is an examination of the influence of confusing questions often used by attorneys to examine witnesses in court. Participants viewed a videotaped incident and were questioned about the incident 1 week later. Half the participants were asked questions framed in a confusing form; the remaining half were asked the same questions in straightforward language. Confusing questions reduced the participant witnesses' accuracy and suppressed the confidence-accuracy relationships compared with the condition in which simple questions were asked. However, the number of absolutely sure responses was the same in both conditions, although these responses were almost always accurate in the simplified condition, whereas in the confusing question condition, accuracy was comparatively poor. This experiment demonstrates the importance of ensuring that lawyers ask witnesses simple, clear questions.     

Remembering with a friend or a stranger: comparing acquainted and unacquainted pairs in collaborative eyewitness interviews

ABSTRACT

Previous findings show that collaborative interviews with pairs of eyewitnesses can result in more accurate testimony than individual interviews, and that partners remember more together if they acknowledge, repeat, rephrase and elaborate upon each other's contributions. In the present study, we investigated whether these findings differ for pairs of acquainted and unacquainted partners, respectively. Participants viewed a violent movie in the cinema and took part in three eyewitness interviews approximately five days later. The first and the last interview were always individual. The second interview was individual in the nominal condition (N?=?22 pairs), collaborative with a known partner in the acquainted condition (N?=?21 pairs), and collaborative with a stranger in the unacquainted condition (N?=?20 pairs). We replicated benefits of collaborative eyewitness interviews, in terms of error pruning as well as delayed cross-cuing. However, we found no significant differences between acquainted and unacquainted pairs, neither in recall performance nor in retrieval strategies during the collaborative interview. Regardless of acquaintance, pairs who elaborated upon each other's contributions during the collaborative interview, remembered more together. The findings are evaluated within the theoretical framework of transactive memory. Practical implications for investigative interviewers are discussed.