The confidence-accuracy relationship in eyewitness identification: effects of lineup instructions, foil similarity, and target-absent base rates

New Insights on Expert Opinion About Eyewitness Memory Research

Experimental psychologists investigating eyewitness memory have periodically gathered their thoughts on a variety of eyewitness memory phenomena. Courts and other stakeholders of eyewitness research rely on the expert opinions reflected in these surveys to make informed decisions. However, the last survey of this sort was published more than 20 years ago, and the science of eyewitness memory has developed since that time. Stakeholders need a current database of expert opinions to make informed decisions. In this article, we provide that update. We surveyed 76 scientists for their opinions on eyewitness memory phenomena. We compared these current expert opinions to expert opinions from the past several decades. We found that experts today share many of the same opinions as experts in the past and have more nuanced thoughts about two issues. Experts in the past endorsed the idea that confidence is weakly related to accuracy, but experts today acknowledge the potential diagnostic value of initial confidence collected from a properly administered lineup. In addition, experts in the past may have favored sequential over simultaneous lineup presentation, but experts today are divided on this issue. We believe this new survey will prove useful to the court and to other stakeholders of eyewitness research.

The effects of non-diagnostic information on confidence and decision making

Many decision-making tasks are characterized by a combination of diagnostic and non-diagnostic information, yet models of responding and confidence almost exclusively focus on the contribution of diagnostic information (e.g., evidence associated with stimulus discriminability), largely ignoring the contribution of non-diagnostic information. An exception is Baranski and Petrusic's Journal of Experimental Psychology: Human Perception and Performance, 24(3), 929-945, (1998) doubt-scaling model, which predicts a negative relationship between non-diagnostic information and confidence, and between non-diagnostic information and accuracy. In two perceptual-choice tasks, we tested the effects of manipulating non-diagnostic information on confidence, accuracy and response time (RT). In Experiment 1, participants viewed a dynamic grid consisting of flashing blue, orange and white pixels and indicated whether the stimulus was predominantly blue or orange (using a response scale ranging from low-confidence blue to high-confidence orange), with the white pixels constituting non-diagnostic information. Increasing non-diagnostic information reduced both confidence and accuracy, generally slowed RTs, and led to an increase in the speed of errors. Experiment 2 replicated these results for a decision-only task, providing further support for the doubt-scaling model of confidence.

Metamnemonic predictions of lineup identification

After a crime is committed, investigators may query witnesses about whether they believe they will be to identify the perpetrator. However, we know little about how such metacognitive judgments are related to performance on a subsequent lineup identification task. The extant research has found the strength of this relationship to be small or nonexistent, which conflicts with the large body of literature indicating a moderate relationship between predictions and performance on memory tasks. In Studies 1-3, we induce variation in encoding quality by having participants watch a mock crime video with either low, medium, or high exposure quality, and then assess their future lineup performance. Calibration analysis revealed that assessments of future lineup performance were predictive of identification accuracy. This relationship was driven primarily by poor performance following low assessments. Studies 4 and 5 showed that these predictions are not based on a witness's evaluation of their encoding experience, nor on a contemporaneous assessment of memory strength. These results reinforce the argument that variation in memory quality is needed to obtain reliable relationships between predictions and performance. An unexpected finding is that witnesses who made a prediction shortly after encoding evinced superior memory compared to those who made a prediction later.

Autistic adults' perspectives on appropriate empathic responses to others' emotions

Although the ability of autistic adults to recognize others' emotions has been extensively studied, less attention has been given to how they respond to these emotions. We examined two aspects of autistic and non-autistic adults' responsiveness to the emotional expressions of non-autistic actors: their perspectives on the appropriate way of responding to others' emotions and their awareness of others' perceptions of the likely appropriateness of such responses. Autistic (N = 63) and non-autistic (N = 67) adult samples viewed videos of 74 dyadic social interactions displaying different examples of 12 emotions expressed by one actor in response to the behavior of the other. After each video, participants (a) nominated the emotion expressed by the first actor, (b) offered their perspective on what would constitute an appropriate empathic response by the second actor, and (c) indicated their confidence in that response. Although the autistic group provided fewer appropriate empathic responses-operationalized via a panel's interpretations of normative responses-than the non-autistic group, within-group variability was marked, and the effect was weak and largely confined to basic emotions. Autistic individuals were, however, considerably less confident in their responses. Examination of the relationships between confidence in and the appropriateness of empathic responses provided no indication in either group of reliable discrimination of appropriate from inappropriate empathic responses or finely tuned metacognitive awareness of variations in appropriateness. In sum, autistic adults' perspectives on the appropriate empathic reactions to non-autistic adults' emotions were not unilaterally or markedly different to those of non-autistic adults.

Measuring lineup fairness from eyewitness identification data using a multinomial processing tree model

The mock-witness task is typically used to evaluate the fairness of lineups. However, the validity of this task has been questioned because there are substantial differences between the tasks for mock witnesses and eyewitnesses. Unlike eyewitnesses, mock witnesses must select a person from the lineup and are alerted to the fact that one lineup member might stand out from the others. It therefore seems desirable to base conclusions about lineup fairness directly on eyewitness data rather than on mock-witness data. To test the importance of direct measurements of biased suspect selection in eyewitness identification decisions, we assessed the fairness of lineups containing either morphed or non-morphed fillers using both mock witnesses and eyewitnesses. We used Tredoux's E and the proportion of suspect selections to measure lineup fairness from mock-witness choices and the two-high threshold eyewitness identification model to measure the biased selection of the suspects directly from eyewitness identification decisions. Results obtained in the mock-witness task and the model-based analysis of data obtained in the eyewitness task converged in showing that simultaneous lineups with morphed fillers were significantly more unfair than simultaneous lineups with non-morphed fillers. However, mock-witness and eyewitness data converged only when the eyewitness task mimicked the mock-witness task by including pre-lineup instructions that (1) discouraged eyewitnesses to reject the lineups and (2) alerted eyewitnesses that a photograph might stand out from the other photographs in the lineup. When a typical eyewitness task was created by removing these two features from the pre-lineup instructions, the morphed fillers no longer lead to unfair lineups. These findings highlight the differences in the cognitive processes of mock witnesses and eyewitnesses and they demonstrate the importance of measuring lineup fairness directly from eyewitness identification decisions rather than indirectly using the mock-witness task.

The effect of pre-event instructions on eyewitness identification

Research on eyewitness identification often involves exposing participants to a simulated crime and later testing memory using a lineup. We conducted a systematic review showing that pre-event instructions, instructions given before event exposure, are rarely reported and those that are reported vary in the extent to which they warn participants about the nature of the event or tasks. At odds with the experience of actual witnesses, some studies use pre-event instructions explicitly warning participants of the upcoming crime and lineup task. Both the basic and applied literature provide reason to believe that pre-event instructions may affect eyewitness identification performance. In the current experiment, we tested the impact of pre-event instructions on lineup identification decisions and confidence. Participants received non-specific pre-event instructions (i.e., "watch this video") or eyewitness pre-event instructions (i.e., "watch this crime video, you'll complete a lineup later") and completed a culprit-absent or -present lineup. We found no support for the hypothesis that participants who receive eyewitness pre-event instructions have higher discriminability than participants who receive non-specific pre-event instructions. Additionally, confidence-accuracy calibration was not significantly different between conditions. However, participants in the eyewitness condition were more likely to see the event as a crime and to make an identification than participants in the non-specific condition. Implications for conducting and interpreting eyewitness identification research and the basic research on instructions and attention are discussed.

Evaluating earwitness identification procedures: adapting pre-parade instructions and parade procedure

Voice identification parades can be unreliable, as earwitness responses are error-prone. In this paper we tested performance across serial and sequential procedures, and varied pre-parade instructions, with the aim of reducing errors. The participants heard a target voice and later attempted to identify it from a parade. In Experiment 1 they were either warned that the target may or may not be present (standard warning) or encouraged to consider responding "not present" because of the associated risk of a wrongful conviction (strong warning). Strong warnings prompted a conservative criterion shift, with participants less likely to make a positive identification regardless of whether the target was present. In contrast to previous findings, we found no statistically reliable difference in accuracy between serial and sequential parades. Experiment 2 ruled out a potential confound in Experiment 1. Taken together, our results suggest that adapting pre-parade instructions provides a simple way of reducing the risk of false identifications.

Experimental validation of a multinomial processing tree model for analyzing eyewitness identification decisions

To improve police protocols for lineup procedures, it is helpful to understand the processes underlying eyewitness identification performance. The two-high threshold (2-HT) eyewitness identification model is a multinomial processing tree model that measures four latent cognitive processes on which eyewitness identification decisions are based: two detection-based processes (the detection of culprit presence and absence) and two non-detection-based processes (biased and guessing-based selection). The model takes into account the full 2 × 3 data structure of lineup procedures, that is, suspect identifications, filler identifications and rejections in both culprit-present and culprit-absent lineups. Here the model is introduced and the results of four large validation experiments are reported, one for each of the processes specified by the model. The validation experiments served to test whether the model’s parameters sensitively reflect manipulations of the processes they were designed to measure. The results show that manipulations of exposure duration of the culprit’s face at encoding, lineup fairness, pre-lineup instructions and ease of rejection of culprit-absent lineups were sensitively reflected in the parameters representing culprit-presence detection, biased suspect selection, guessing-based selection and culprit-absence detection, respectively. The results of the experiments thus validate the interpretations of the parameters of the 2-HT eyewitness identification model.

A validation of the two-high threshold eyewitness identification model by reanalyzing published data

The two-high threshold (2-HT) eyewitness identification model serves as a new measurement tool to measure the latent cognitive processes underlying eyewitness identification performance. By simultaneously taking into account correct culprit identifications, false innocent-suspect identifications, false filler identifications in culprit-present and culprit-absent lineups as well as correct and false lineup rejections, the model capitalizes on the full range of data categories that are observed when measuring eyewitness identification performance. Thereby, the model is able to shed light on detection-based and non-detection-based processes underlying eyewitness identification performance. Specifically, the model incorporates parameters for the detection of culprit presence and absence, biased selection of the suspect and guessing-based selection among the lineup members. Here, we provide evidence of the validity of each of the four model parameters by applying the model to eight published data sets. The data sets come from studies with experimental manipulations that target one of the underlying processes specified by the model. Manipulations of encoding difficulty, lineup fairness and pre-lineup instructions were sensitively reflected in the parameters reflecting culprit-presence detection, biased selection and guessing-based selection, respectively. Manipulations designed to facilitate the rejection of culprit-absent lineups affected the parameter for culprit-absence detection. The reanalyses of published results thus suggest that the parameters sensitively reflect the manipulations of the processes they were designed to measure, providing support of the validity of the 2-HT eyewitness identification model.

Facing up to others' emotions: No evidence of autism-related deficits in metacognitive awareness of emotion recognition

Emotion recognition difficulties are considered to contribute to social‐communicative problems for autistic individuals and awareness of such difficulties may be critical for the identification and pursuit of strategies that will mitigate their adverse effects. We examined metacognitive awareness of face emotion recognition responses in autistic (N = 63) and non‐autistic (N = 67) adults across (a) static, dynamic and social face emotion stimuli, (b) free‐ and forced‐report response formats, and (c) four different sets of the six “basic” and six “complex” emotions. Within‐individual relationships between recognition accuracy and post‐recognition confidence provided no indication that autistic individuals were poorer at discriminating correct from incorrect recognition responses than non‐autistic individuals, although both groups exhibited marked inter‐individual variability. Although the autistic group was less accurate and slower to recognize emotions, confidence‐accuracy calibration analyses provided no evidence of reduced sensitivity on their part to fluctuations in their emotion recognition performance. Across variations in stimulus type, response format and emotion, increases in accuracy were associated with progressively higher confidence, with similar calibration curves for both groups. Calibration curves for both groups were, however, characterized by overconfidence at the higher confidence levels (i.e., overall accuracy less than the average confidence level), with the non‐autistic group contributing more decisions with 90%–100% confidence. Comparisons of slow and fast responders provided no evidence of a “hard‐easy” effect—the tendency to exhibit overconfidence during hard tasks and underconfidence during easy tasks—suggesting that autistic individuals' slower recognition responding may reflect a strategic difference rather than a processing speed limitation.

Lineup identification in young and older witnesses: does describing the criminal help or hinder?

The world population is getting older and, as a result, the number of older victims of crime is expected to increase. It is therefore essential to understand how ageing affects eyewitness identification, so procedures can be developed that enable victims of crime of all ages to provide evidence as accurately and reliably as possible. In criminal investigations, witnesses often provide a description of the perpetrator of the crime before later making an identification. While describing the perpetrator prior to making a lineup identification can have a detrimental effect on identification in younger adults, referred to as verbal overshadowing, it is unclear whether older adults are affected in the same way. Our study compared lineup identification of a group of young adults and a group of older adults using the procedure that has consistently revealed verbal overshadowing in young adults. Participants watched a video of a mock crime. Following a 20-min filled delay, they either described the perpetrator or completed a control task. Immediately afterwards, they identified the perpetrator from a lineup, or indicated that the perpetrator was not present, and rated their confidence. We found that describing the perpetrator decreased subsequent correct identification of the perpetrator in both young and older adults. This effect of verbal overshadowing was not explained by a change in discrimination but was consistent with participants adopting a more conservative criterion. Confidence and response time were both found to predict identification accuracy for young and older groups, particularly in the control condition.

The benefits of errors during training

Errors are generally not thought of as a positive thing - not in society at large, and especially not in forensic science. However, there is a large body of literature in the field of cognitive science (particularly from psychology and education research) that highlights the benefits that can be gained from using errors made in training to improve learning. Although none of these studies was done directly in the forensic science disciplines, there are nonetheless lessons to be learned about how errors may most effectively be used to maximize their benefits to learning. This article presents an overview of the literature on learning from errors and suggests principles that may be of benefit to forensic science today, as well as suggesting areas where specific research may be of benefit to forensic science in the future.

Test a Witness's Memory of a Suspect Only Once

Eyewitness misidentifications are almost always made with high confidence in the courtroom. The courtroom is where eyewitnesses make their last identification of defendants suspected of (and charged with) committing a crime. But what did those same eyewitnesses do on the first identification test, conducted early in a police investigation? Despite testifying with high confidence in court, many eyewitnesses also testified that they had initially identified the suspect with low confidence or failed to identify the suspect at all. Presenting a lineup leaves the eyewitness with a memory trace of the faces in the lineup, including that of the suspect. As a result, the memory signal generated by the face of that suspect will be stronger on a later test involving the same witness, even if the suspect is innocent. In that sense, testing memory contaminates memory. These considerations underscore the importance of a newly proposed recommendation for conducting eyewitness identifications: Avoid repeated identification procedures with the same witness and suspect. This recommendation applies not only to additional tests conducted by police investigators but also to the final test conducted in the courtroom, in front of the judge and jury.

Missing children appeal designs: Is recall accuracy influenced by the design of the appeal?

When a child goes missing it is common practice to release an appeal of the child in the hope that a member of the public could help to identify and locate them. Despite being an everyday occurrence, there remains a significant gap in our understanding of how effective these appeals are. The present study sought to explore the effectiveness of missing children appeals through the recall accuracy of the general public immediately after observing the appeals and again after a three-day delay. One hundred and eighty-two participants observed either a mock Child Rescue Alert or a mock Twitter appeal. The results found no significant difference in recall accuracy between the design of the appeals although there was a significant difference in recall error. Confidence in own recall accuracy and the length of time spent observing the appeals were also found to be significantly associated with recall accuracy. Initial recall accuracy scores were significantly higher than recall accuracy scores following a three-day break. This exploratory study demonstrates the requirement to improve missing children appeals and lays the foundation for future studies to build on these findings further.

Perpetrator pose reinstatement during a lineup test increases discrimination accuracy

We examined how encoding view influences the information that is stored in and retrieved from memory during an eyewitness identification task. Participants watched a mock crime and we varied the angle from which they viewed the perpetrator. In Experiment 1, participants (N = 2904) were tested with a static photo lineup; the viewing angle of the lineup members was the same or different from the perpetrator at encoding. In Experiment 2, participants (N = 1430) were tested with a novel interactive lineup in which they could rotate the lineup faces into any angle. In both experiments, discrimination accuracy was greater when the viewing angle at encoding and test matched. Participants reinstated the angle of the interactive faces to match their encoding angle. Our results highlight the importance of encoding specificity for eyewitness identification, and show that people actively seek out information in the testing environment that matches the study environment to aid memory retrieval.

A Quick Measure of Theory of Mind in Autistic Adults: Decision Accuracy, Latency and Self-Awareness

Autistic adults often experience difficulties in taking the perspective of others, potentially undermining their social interactions. We evaluated a quick, forced-choice version of the Adult Theory of Mind (A-ToM) test, which was designed to assess such difficulties and comprehensively evaluated by Brewer et al. (2017). The forced-choice version (the A-ToM-Q) demonstrated discriminant, concurrent, convergent and divergent validity using samples of autistic (N = 96) and non-autistic adults (N = 75). It can be administered in a few minutes and machine-scored, involves minimal training and facilitates large-scale, live, or web-based testing. It permits measurement of response latency and self-awareness, with response characteristics on both measures enhancing understanding of the nature and extent of perspective taking difficulties in autistic individuals.

Applying confidence accuracy characteristic plots to old/new recognition memory experiments

Confidence-accuracy characteristic (CAC) plots were developed for use in eyewitness identification experiments, and previous findings show that high confidence indicates high accuracy in all studies of adults with an unbiased lineup. We apply CAC plots to standard old/new recognition memory data by calculating response-based and item-based accuracy, one using false alarms and the other using misses. We use both methods to examine the confidence-accuracy relationship for both correct old responses (hits) and new responses (correct rejections). We reanalysed three sets of published data using these methods and show that the method chosen, as well as the relation of lures to targets, determines the confidence-accuracy relation. Using response-based accuracy for hits, high confidence yields quite high accuracy, and this is generally true with the other methods, especially when lures are unrelated to targets. However, when analyzing correct rejections, the relationship between confidence and accuracy is less pronounced. When lures are semantically related to targets, the various CAC plots show different confidence-accuracy relations. The different methods of calculating CAC plots provide a useful tool in analyzing standard old/new recognition experiments. The results generally accord with unequal-variance signal detection models of recognition memory.

Performance of typical and superior face recognizers on a novel interactive face matching procedure

Unfamiliar simultaneous face matching is error prone. Reducing incorrect identification decisions will positively benefit forensic and security contexts. The absence of view-independent information in static images likely contributes to the difficulty of unfamiliar face matching. We tested whether a novel interactive viewing procedure that provides the user with 3D structural information as they rotate a facial image to different orientations would improve face matching accuracy. We tested the performance of 'typical' (Experiment 1) and 'superior' (Experiment 2) face recognizers, comparing their performance using high-quality (Experiment 3) and pixelated (Experiment 4) Facebook profile images. In each trial, participants responded whether two images featured the same person with one of these images being either a static face, a video providing orientation information, or an interactive image. Taken together, the results show that fluid orientation information and interactivity prompt shifts in criterion and support matching performance. Because typical and superior face recognizers both benefited from the structural information provided by the novel viewing procedures, our results point to qualitatively similar reliance on pictorial encoding in these groups. This also suggests that interactive viewing tools can be valuable in assisting face matching in high-performing practitioner groups.

Eyewitness identification performance is not affected by time-of-day optimality

The circadian rhythm regulates arousal levels throughout the day and determines optimal periods for engaging in mental activities. Individuals differ in the time of day at which they reach their peak: Morning-type individuals are at their best in the morning and evening types perform better in the evening. Performance in recall and recognition of non-facial stimuli is generally superior at an individual’s circadian peak. In two studies (Ns = 103 and 324), we tested the effect of time-of-testing optimality on eyewitness identification performance. Morning- and evening-type participants viewed stimulus films depicting staged crimes and made identification decisions from target-present and target-absent lineups either at their optimal or non-optimal time-of-day. We expected that participants would make more accurate identification decisions and that the confidence-accuracy and decision time-accuracy relationships would be stronger at optimal compared to non-optimal time of day. In Experiment 1, identification accuracy was unexpectedly superior at non-optimal compared to optimal time of day in target-present lineups. In Experiment 2, identification accuracy did not differ between the optimal and non-optimal time of day. Contrary to our expectations, confidence-accuracy relationship was generally stronger at non-optimal compared to optimal time of day. In line with our predictions, non-optimal testing eliminated decision-time-accuracy relationship in Experiment 1.

Investigating the ease-of-retrieval effect in an eyewitness context

The way in which individuals think about their own cognitive processes plays an important role in various domains. When eyewitnesses assess their confidence in identification decisions, they could be influenced by how easily relevant information comes to mind. This ease-of-retrieval effect has a robust influence on people's cognitions in a variety of contexts (e.g., attitudes), but it has not yet been applied to eyewitness decisions. In three studies, we explored whether the ease with which eyewitnesses recall certain memorial information influenced their identification confidence assessments and related testimony-relevant judgements (e.g., perceived quality of view). We manipulated the number of reasons participants gave to justify their identification (Study 1; N = 343), and also the number of instances they provided of a weak or strong memory (Studies 2a & 2b; Ns = 350 & 312, respectively). Across the three studies, ease-of-retrieval did not affect eyewitnesses' confidence or other testimony-relevant judgements. We then tried - and failed - to replicate Schwarz, N., Bless, H., Strack, F., Klumpp, G., Rittenauer-Schatka, H., & Simons, A. (1991. Ease of retrieval as information: Another look at the availability heuristic. Journal of Personality and Social Psychology, 61(2), 195-202. doi:10.1037/0022-3514.61.2.195) original ease-of-retrieval finding (Study 3; N = 661). In three of the four studies, ease-of-retrieval had the expected effect on participants' perceived task difficulty; however, frequentist and Bayesian testing showed no evidence for an effect on confidence or assertiveness ratings.

Laypeople's beliefs about the effects of common estimator variables on memory

This research builds on James Ost's research investigating whether laypeople's beliefs align with those of experts. Recent studies that examined the relationship between high-confidence eyewitness identifications and accuracy proposed that the mechanism underlying this relationship may be based on a knowledge-conditional model. According to this model, the accuracy of a confidence judgment depends on knowledge about factors that affect memory accuracy. However, there has not been a comprehensive assessment of laypeople's knowledge about the effect on memory accuracy of many estimator variables known to influence the accuracy of eyewitnesses, specifically those relevant to research on the relationship between witness confidence and accuracy. This study consists of the development of a 30-item scale to assess laypeople's knowledge of the effect of 10 common estimator variables on memory accuracy from three points of view (POV): Self, Other, and Juror. Across MTurk and undergraduate samples, laypeople's beliefs about the effect of these estimator variables were generally consistent with research findings and did not differ as a function of POV. Additionally, for most estimator variables, participants' beliefs about memory were consistent with results in the confidence-accuracy literature; confidence and identification accuracy appear to be poorly calibrated for estimator variables that people know less about.

Estimating the proportion of guilty suspects and posterior probability of guilt in lineups using signal-detection models

Background

The majority of eyewitness lineup studies are laboratory-based. How well the conclusions of these studies, including the relationship between confidence and accuracy, generalize to real-world police lineups is an open question. Signal detection theory (SDT) has emerged as a powerful framework for analyzing lineups that allows comparison of witnesses’ memory accuracy under different types of identification procedures. Because the guilt or innocence of a real-world suspect is generally not known, however, it is further unknown precisely how the identification of a suspect should change our belief in their guilt. The probability of guilt after the suspect has been identified, the posterior probability of guilt (PPG), can only be meaningfully estimated if we know the proportion of lineups that include a guilty suspect, P(guilty). Recent work used SDT to estimate P(guilty) on a single empirical data set that shared an important property with real-world data; that is, no information about the guilt or innocence of the suspects was provided. Here we test the ability of the SDT model to recover P(guilty) on a wide range of pre-existing empirical data from more than 10,000 identification decisions. We then use simulations of the SDT model to determine the conditions under which the model succeeds and, where applicable, why it fails.

Results

For both empirical and simulated studies, the model was able to accurately estimate P(guilty) when the lineups were fair (the guilty and innocent suspects did not stand out) and identifications of both suspects and fillers occurred with a range of confidence levels. Simulations showed that the model can accurately recover P(guilty) given data that matches the model assumptions. The model failed to accurately estimate P(guilty) under conditions that violated its assumptions; for example, when the effective size of the lineup was reduced, either because the fillers were selected to be poor matches to the suspect or because the innocent suspect was more familiar than the guilty suspect. The model also underestimated P(guilty) when a weapon was shown.

Conclusions

Depending on lineup quality, estimation of P(guilty) and, relatedly, PPG, from the SDT model can range from poor to excellent. These results highlight the need to carefully consider how the similarity relations between fillers and suspects influence identifications.

Convicting with confidence? Why we should not over-rely on eyewitness confidence

Eyewitness memory researchers have recently devoted considerable attention to eyewitness confidence. While there is strong consensus that courtroom confidence is problematic, we now recognise that an eyewitness's initial confidence in their first identification - in certain contexts - can be of value. A few psychological scientists, however, have confidently, but erroneously claimed that in real-world cases, eyewitness initial confidence is the most important indicator of eyewitness accuracy, trumping all other factors that might exist in a case. This claim accompanies an exaggeration of the role of eyewitnesses' "initial confidence" in the DNA exoneration cases. Still worse, overstated claims about the confidence-accuracy relationship, and eyewitness memory, have reached our top scientific journals, news articles, and criminal cases. To set the record straight, we review what we actually know and do not know about the "initial confidence" of eyewitnesses in the DNA exoneration cases. Further reasons for skepticism about the value of the confidence-accuracy relationship in real-world cases come from new analyses of a separate database, the National Registry of Exonerations. Finally, we review new research that reveals numerous conditions wherein eyewitnesses with high initial confidence end up being wrong.

Metacognition of average face perception

Individuals have the ability to extract summary statistics from multiple items presented simultaneously. However, it is unclear yet whether we have insight into the process of ensemble coding. The aim of this study was to investigate metacognition about average face perception. Participants saw a group of four faces presented for 2 s or 5 s, and then they were asked to judge whether the following test face was present in the previous set (Experiment 1), or whether the test face was the average of the four member faces (Experiment 2). After each response, participants rated their confidence. Replicating previous findings, there was substantial endorsement for the average face derived from the four member faces in Experiment 1, even though it was not present in the set. When judging faces that had been presented in the set, confidence correlated positively with accuracy, providing evidence for metacognitive awareness of previously studied faces. Importantly, there was a negative confidence-accuracy relationship for judging average faces when duration was 2 s, and a near-zero relationship when duration was 5 s. By contrast, when the average face had to be identified explicitly in Experiment 2, performance was above chance level and there was a positive correlation between confidence and accuracy. These results suggest that people have metacognitive awareness about average face perception when averaging is required explicitly, but they lack insight into the averaging process when member identification is required.

May I Speak Freely? The Difficulty in Vocal Identity Processing Across Free and Scripted Speech

In the fields of face recognition and voice recognition, a growing literature now suggests that the ability to recognize an individual despite changes from one instance to the next is a considerable challenge. The present paper reports on one experiment in the voice domain designed to determine whether a change in the mere style of speech may result in a measurable difficulty when trying to discriminate between speakers. Participants completed a speaker discrimination task to pairs of speech clips, which represented either free speech or scripted speech segments. The results suggested that speaker discrimination was significantly better when the style of speech did not change compared to when it did change, and was significantly better from scripted than from free speech segments. These results support the emergent body of evidence suggesting that within-identity variability is a challenge, and the forensic implications of such a mild change in speech style are discussed.

Distinguishing Between Investigator Discriminability and Eyewitness Discriminability: A Method for Creating Full Receiver Operating Characteristic Curves of Lineup Identification Performance

The conceptual frameworks provided by both the lineups-as-experiments analogy and signal detection theory have proven important to understanding how eyewitness lineups work. The lineups-as-experiments analogy proposes that when investigators use a lineup procedure, they are acting as experimenters and should therefore follow the same tried-and-true procedures that experimenters follow when executing an experiment. Signal detection theory offers a framework for distinguishing between factors that improve the trade-off between culprit and innocent-suspect identifications and factors that affect the frequency of suspect identifications. We integrate these two conceptual frameworks. We argue that an eyewitness lineup procedure is characterized by two simultaneous signal detection tasks. On one hand, the witness is tasked with determining whether the culprit is present in the lineup and identifying that person. On the other hand, the investigator knows which lineup member is the suspect and which lineup members are known-innocent fillers and is therefore tasked only with determining whether the suspect is the culprit. The investigator uses the witness's identification decision and associated level of confidence to decide whether the suspect is the culprit. We leverage this realization to demonstrate a method for creating full receiver operating characteristic curves for eyewitness lineup procedures.

Voice parade procedures: optimising witness performance

Unfamiliar voice identification is error-prone. Whilst the investigation of system variables may indicate ways of boosting earwitness performance, this is an under-researched area. Two experiments were conducted to investigate how methods of presenting voices during a parade affect accuracy and self-rated confidence. In each experiment participants listened to a target voice, and were later asked to identify that voice from a nine-person target present or target absent parade. In Experiment 1, accuracy did not vary across parades comprising 15 or 30 s sample durations. Overall, when the target was present, participants correctly identified the target voice with 39% accuracy. However, when the target was absent, participants correctly rejected the parade 6% of the time. There was no relationship between accuracy and confidence. In Experiment 2, performance with a serial procedure, in which participants responded after hearing all nine voices, was compared with a sequential procedure, in which participants made a decision after listening to each voice. Overall accuracy was higher with the sequential procedure. These results highlight the importance of system variable research in voice identification. Different methods of presenting voices have the potential to support higher levels of accuracy than the procedure currently recommended in England and Wales.

Confidence Can Be Used to Discriminate Between Accurate and Inaccurate Lie Decisions

There is a long-standing belief that confidence is not useful at discriminating between accurate and inaccurate deception decisions. Historically, this position made sense because people showed little ability to discriminate lie-tellers from truth-tellers. But, it is now widely accepted that, under certain conditions, people can discriminate between lie-tellers and truth-tellers. Nevertheless, belief that confidence does not discriminate between accurate and inaccurate responses persists. This belief is somewhat paradoxical because, to the extent that people can discriminate between lie-tellers and truth-tellers, signal detection theory naturally predicts a positive relationship between confidence and accuracy. In line with our signal-detection-based predictions, we show that, among decisions about whether someone is lying, those made with high confidence are more accurate than those made with low confidence. This important relationship has gone unnoticed in past work because of a reliance on inappropriate measures. Past research examining the confidence-accuracy relationship in deception research relied on correlating average confidence with proportion of correctly identified lies. These correlations provide information on whether more confident judges tend to be more accurate but remain silent on the arguably more important question of whether higher confidence decisions are more accurate than lower confidence decisions. We show that confidence-accuracy characteristic analyses are uniquely suited to measuring the confidence-accuracy relationship in deception research.

Developmental trends in lineup performance: Adolescents are more prone to innocent bystander misidentifications than children and adults

We tested developmental trends in eyewitness identification in biased and unbiased lineups. Our main interest was adolescent's lineup performance compared with children and adults. 7-10-year-olds, 11-13-year-olds, 14-16-year-olds, and adults (N = 431) watched a wallet-theft-video and subsequently identified the thief, victim, and witness from simultaneous target-present and target-absent six-person photo lineups. The thief-absent lineup included a bystander previously seen in thief proximity. Research on unconscious transference suggested a selection bias toward the bystander in adults and 11-13-year-olds, but not in younger children. Confirming our hypothesis, adolescents were more prone to bystander bias than all other age groups. This may be due to adolescents making more inferential errors than children, as predicted by fuzzy-trace theory and associative-activation theory, combined with lower inhibition control in adolescents compared with adults. We also replicated a clothing bias for all age groups and age-related performance differences in our unbiased lineups. Consistent with previous findings, participants were generally overconfident in their decisions, even though confidence was a better predictor of accuracy in older compared with younger participants. With this study, we show that adolescents have an increased tendency to misidentify an innocent bystander. Continued efforts are needed to disentangle how adolescents in comparison to other age groups perform in forensically relevant situations.

Does anyone else look familiar? Influencing identification decisions by asking witnesses to re-examine the lineup

Two experiments were conducted to see if asking witnesses to take another look at the lineup after they voiced their identification decisions would alter their choices, and if confirming feedback could then be used to solidify the selections they shifted to. Participants watched a simulated crime and were asked to identify the culprit from a photographic lineup. After voicing their identification decisions, participants were prompted to re-examine the lineup. Half of the participants then received confirming feedback for their decisions, regardless of whether they shifted to a new picture or not. Later on, a different experimenter escorted participants to a second room and administered the same lineup again. In Experiment 1 (N = 432), biased instructions were used to encourage choosing, and when participants were prompted to re-examine the lineup, 70% changed their identification decisions and selected a different picture. When that new selection was reinforced with feedback and participants were given a second opportunity to identify the culprit at a later time, 72% selected the picture they shifted to as the culprit. Participants who made their decisions more quickly were less likely to shift, but accuracy did not predict shifting. This general pattern of findings was replicated using unbiased instructions in Experiment 2 (N = 237). Results suggest that prompting witnesses to re-examine the lineup can often lead witnesses to change their identification decisions, and when the altered choice is reinforced, they will often stay with that influenced decision over time, asserting it with a high degree of confidence. (PsycINFO Database Record

Warnings to Counter Choice Blindness for Identification Decisions: Warnings Offer an Advantage in Time but Not in Rate of Detection

Choice blindness for identification decisions refers to the inability of eyewitnesses to detect that an originally recognized target was swapped for a non-identified lineup member. The robustness of the effect calls for measures that can prevent or reduce the negative consequences of choice blindness manipulations. Here, we investigated whether pre- and post-warnings given to participants about the possibility of mistakes reduces choice blindness for identification decisions. Participants (N = 119) were presented with identifications they never made and were asked to justify those decisions. Either before or after the presentation of the manipulated identification outcome, participants were or were not warned about the possibility of mistakes in the identification process. Although warnings were not sufficient to reduce choice blindness for identification decisions they provided a time-related detection advantage. Pre-warned participants questioned the legitimacy of the manipulated outcome sooner (i.e., concurrent detection) than participants in other conditions. Hence, pre-warnings can help detect mistakes in the identification procedure at an earlier stage, before they contaminate the memory of the witness and other pieces of evidence. From a theoretical stance, our findings attest to the strength of self-suggestion and indicate that choice blindness effects are deeply rooted in cognition.

Decision time and confidence predict choosers' identification performance in photographic showups

In vast contrast to the multitude of lineup studies that report on the link between decision time, confidence, and identification accuracy, only a few studies looked at these associations for showups, with results varying widely across studies. We therefore set out to test the individual and combined value of decision time and post-decision confidence for diagnosing the accuracy of positive showup decisions using confidence-accuracy characteristic curves and Bayesian analyses. Three-hundred-eighty-four participants viewed a stimulus event and were subsequently presented with two showups which could be target-present or target-absent. As expected, we found a negative decision time-accuracy and a positive post-decision confidence-accuracy correlation for showup selections. Confidence-accuracy characteristic curves demonstrated the expected additive effect of combining both postdictors. Likewise, Bayesian analyses, taking into account all possible target-presence base rate values showed that fast and confident identification decisions were more diagnostic than slow or less confident decisions, with the combination of both being most diagnostic for postdicting accurate and inaccurate decisions. The postdictive value of decision time and post-decision confidence was higher when the prior probability that the suspect is the perpetrator was high compared to when the prior probability that the suspect is the perpetrator was low. The frequent use of showups in practice emphasizes the importance of these findings for court proceedings. Overall, these findings support the idea that courts should have most trust in showup identifications that were made fast and confidently, and least in showup identifications that were made slowly and with low confidence.

Diagnosing Crime and Diagnosing Disease-II: Visual Pattern Perception and Diagnostic Accuracy

Previously, we reviewed how general cognitive processes might be susceptible to bias across both forensic and clinical fields, and how interdisciplinary comparisons could reduce error. We discuss several examples of clinical tasks which are heavily dependent on visual processing, comparing them to eyewitness identification (EI). We review the "constructive" nature of visual processing, and how contextual factors influence both medical experts and witnesses in decision making and recall. Overall, studies suggest common cognitive factors uniting these visual tasks, in both their strengths and shortcomings. Recently forensic sciences have advocated reducing errors by identifying and controlling nonrelevant information. Such efforts could effectively assist medical diagnosis. We suggest potential remedies for cognitive bias in these tasks. These can generalize across the clinical and forensic domains, including controlling the sequencing of contextual factors. One solution is an agnostic primary reading before incorporation of a complete history and interpretation.

The Relationship Between Clinicians' Confidence and Accuracy, and the Influence of Child Characteristics, in the Screening of Autism Spectrum Disorder

The study examined the confidence accuracy relationship, and the influence of child characteristics on clinician confidence, when predicting a diagnosis of Autism Spectrum Disorder during screening of 125 referred children aged under 3.5 years. The diagnostic process included observation, interview, language and developmental testing. Clinical judgement accuracy was compared against final diagnosis for high and low confidence levels (with confidence assessed on a 0-100 % scale). We identified a significant CA relationship with predictive accuracy highest at confidence levels of 90-100 %. Parent report of unusual behaviors was the only significant independent predictor of confidence. Clinicians' confidence may be important when evaluating decisions to refer, or not to refer, children for further diagnostic assessment.

Overdistribution illusions: Categorical judgments produce them, confidence ratings reduce them

Overdistribution is a form of memory distortion in which an event is remembered as belonging to too many episodic states, states that are logically or empirically incompatible with each other. We investigated a response formatting method of suppressing 2 basic types of overdistribution, disjunction and conjunction illusions, which parallel some classic illusions in the judgment and decision making literature. In this method, subjects respond to memory probes by rating their confidence that test cues belong to specific episodic states (e.g., presented on List 1, presented on List 2), rather than by making the usual categorical judgments about those states. The central prediction, which was derived from the task calibration principle of fuzzy-trace theory, was that confidence ratings should reduce overdistribution by diminishing subjects' reliance on noncompensatory gist memories. The data of 3 experiments agreed with that prediction. In Experiment 1, there were reliable disjunction illusions with categorical judgments but not with confidence ratings. In Experiment 2, both response formats produced reliable disjunction illusions, but those for confidence ratings were much smaller than those for categorical judgments. In Experiment 3, there were reliable conjunction illusions with categorical judgments but not with confidence ratings. Apropos of recent controversies over confidence-accuracy correlations in memory, such correlations were positive for hits, negative for correct rejections, and the 2 types of correlations were of equal magnitude. (PsycINFO Database Record