Witnesses' failure to detect covert manipulations in their written statements

Law enforcement agencies and legal professionals often have to rely on witness statements. Undetected errors in witnesses' statements, however, could impede the accurate reconstruction of a crime and lead to the incrimination of innocent suspects. Here, we examined whether witnesses can detect manipulations in their written statements. We expect that writing a statement could provide a good means for discrimination between what is truly recalled and what is an error. This is because writing allows to monitor and control the previously produced information. In 3 experiments, participants watched a mock crime film and subsequently provided a written statement of what they had witnessed. Following a delay of several minutes (Experiment 1), 48hr (Experiment 2), or 1month (Experiment 3), participants were exposed to and interviewed about their testimony. Unknown to them, they were confronted with statements, which included 4 secretly manipulated details. Participants' missed a substantial number of manipulations in their written statements. Importantly, the detection rates varied as a function of delay (Experiments 1 and 2: 74-89%; Experiment 3: 36%-52%). Detection rates also varied as a function of the type of details that were manipulated. Our findings indicate that writing a statement comes with limited benefits in witnesses' ability to detect errors in their statements

Expert witnesses, dissociative amnesia, and extraordinary remembering:response to Brand et al.

status: publishe

The verifiability approach to detection of malingered physical symptoms

Inspired by recent research showing that liars are reluctant to include verifiable details in their accounts, we explored in two studies (N =125; N = 105) whether participants who report fabricated symptoms (‘malingerers’) present fewer verifiable details than participants who report genuine ill-health symptoms. In Study 1, participants were instructed to describe a typical day on which they had experienced a genuine or malingered symptom. Truth tellers’ statements included significantly higher proportions of verifiable details concerning the reported symptoms than malingerers’ statements. Compared with truth tellers, malingerers generated longer statements with more unverifiable details. In Study 2, we informed participants that their statements may be assessed for verifiable or checkable details. Malingerers often mentioned ‘false’ witnesses to provide checkable information and differences between malingerers and truth tellers in statement length, and checkable and uncheckable details were no longer significant. The utility and implications of the Verifiability Approach to detection of malingering are discussed

Detecting feigned high impact experiences: a symptom over-report questionnaire outperforms the emotional Stroop task

BACKGROUND AND OBJECTIVES: The Modified Stroop Task (MST) effect refers to a prolonged reaction time (RT) in color-naming words related to an individual's disorder. Some authors argue that its absence in people who claim symptoms might be an indication of feigning. METHOD: We tested whether the MST effect is robust against feigning attempts and compared its absence as an index of feigning with over-reporting tendencies on a symptom questionnaire (i.e., the Self-Reported Symptom Inventory (SRSI)). We included participants (n = 22) who i) reported current high impact of aversive experiences (High scorers), ii) reported current low impact (Low scorers) of aversive experiences (n = 24), and iii) actors (n = 18) with low impact, but instructed to feign current high psychological impact of aversive life events (Simulators). We administered the MST, including impact-related, neutral, and feigning-related words, and the SRSI. RESULTS: We found no MST effect for impact-related words in the high scorers group, or for feigning-related words in the simulators. Relative to high scorers and low scorers, simulators exhibited significantly longer RTs on all types of words and they also endorsed significantly more bogus symptoms on the SRSI. Thus, the SRSI was a more sensitive measure of feigning than the absence of an MST effect. LIMITATION: Some limitations are related to our reliance on a sub-clinical student sample, whereas others reflect the unresolved issues surrounding the MST. Thus, the generalizability of our results is uncertain. CONCLUSION: Our findings add to the doubts on the idea that the MST can be used to differentiate between genuine and feigned complaints

Verifiability on the run: an experimental study on the verifiability approach to malingered symptoms

Several studies on the verifiability approach found that truth-tellers report more verifiable details than liars. Therefore, we wanted to test whether such a difference would emerge in the context of malingered symptoms. We obtained statements from undergraduates (N D 53) who had been allocated to three different conditions: truth-tellers, coached malingerers and na ıve malingerers. Truth-tellers carried out an intensive physical exercise and after a short interval wrote a report about their experience and elicited symptoms. The two malingering groups had to fabricate a story about the physical activity and its symptoms. Truth-tellers did not generate more verifiable details than malingerers. However, malingerers reported more non-verifiable details than truth-tellers. Coached and na ıve malingerers did not differ in this respect. Relative to truth-tellers, na ıve malingerers reported more symptoms-related nonverifiable details, while coached malingerers reported more exercise-related non-verifiable details. Focusing on non-verifiable details may inform the detection of malingered symptoms.This work was supported by the House of Legal Psychology/Erasmus Mundus Joint Doctorate [Framework Partnership Agreement (FPA) 2013- 0036]; [Cohort 2015 with Specific Grant Agreement (SGA) 2015-1610]

Brief report: Writing about chronic fatigue increases somatic complaints

Participants were instructed to imagine that either they or a friend were suffering from chronic fatigue syndrome (CFS) and were asked to fabricate a story about how CFS affected their own or their friend\u27s daily functioning. Control participants were not given an imagination exercise but were asked to write about their study choice. After the writing exercise, all participants completed the Symptom Checklist-90 (SCL-90). Participants who had written a story about how CFS symptoms affected daily life (either their own life or that of a friend) had higher scores on the Somatization subscale of the SCL-90 than controls. This finding resembles the misinformation effect documented by memory research, and suggests that elaborative writing about illness, through its symptom-escalating power, has iatrogenic potential.</p