Glynis Bogaard

Strong, but wrong:lay people’s and police officers’ beliefs about verbal and nonverbal cues to deception

The present study investigated the beliefs of students and police officers about cues to deception. A total of 95 police officers and 104 undergraduate students filled out a questionnaire addressing beliefs about cues to deception. Twenty-eight verbal cues were included in the questionnaire, all extracted from verbal credibility assessment tools (i.e., CBCA, RM, and SCAN). We investigated to what extent beliefs about nonverbal and verbal cues of deception differed between lay people (students) and police officers, and whether these beliefs were in agreement with objective cues known from research. Both students and police officers believed the usual stereotypical, but non-diagnostic (nonverbal) cues such as gaze aversion and increased movement to be indicative of deception. Yet, participants were less inclined to overestimate the relationship between verbal cues and deception and their beliefs fitted better with what we know from research. The implications of these findings for practice are discussed.

Scientific Content Analysis (SCAN) Cannot Distinguish Between Truthful and Fabricated Accounts of a Negative Event

The Scientific Content Analysis (SCAN) is a verbal veracity assessment method that is currently used worldwide by investigative authorities. Yet, research investigating the accuracy of SCAN is scarce. The present study tested whether SCAN was able to accurately discriminate between true and fabricated statements. To this end, 117 participants were asked to write down one true and one fabricated statement about a recent negative event that happened in their lives. All statements were analyzed using 11 criteria derived from SCAN. Results indicated that SCAN was not able to correctly classify true and fabricated statements. Lacking empirical support, the application of SCAN in its current form should be discouraged.

SCAN is largely driven by 12 criteria: results from sexual abuse statements

Scientific Content Analysis (SCAN) is increasingly used by investigative authorities to evaluate the credibility of statements made by witnesses and suspects. SCAN, however, lacks a well-defined list of criteria, and does not involve a standardised scoring system. In the current study, we investigated which SCAN criteria are represented in actual statements. To this end, we analysed 82 sexual abuse cases of the Dutch police in which SCAN had been applied. Two independent coders scored the presence of various SCAN criteria in the: (1) written statements from victims, suspects, and witnesses; and also looked at the (2) recommendations for follow-up investigations that were derived from SCAN. Results showed that SCAN is primarily driven by 12 criteria. Results also indicated a low inter-rater agreement for most SCAN criteria, suggesting SCAN is insufficiently developed as a forensic tool. Still, the 12 criteria can be used as a starting point for future research on their psychometric properties.

The Verifiability Approach to detection of malingered physical symptoms

ABSTRACT 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.