Forensic Psychology
Page 42
UN General Assembly (1984). Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment: Resolution/adopted by the General Assembly. 10 December 1984, A/RES/39/46. Retrieved from http://www.ohchr.org/EN/ProfessionalInterest/Pages/CAT.aspx
Vallano, J. P., & Schreiber Compo, N. (2011). A comfortable witness is a good witness: Rapport- building and susceptibility to misinformation in an investigative mock-crime interview. Applied Cognitive Psychology, 25, 960–970.
Vallano, J. P., & Schreiber Compo , N. (2015). Rapport-building with cooperative witnesses and criminal suspects: A theoretical and empirical review. Psychology, Public Policy, and Law, 21, 85.
van der Sleen , J. (2009). A structured model of investigative interviewing of suspects. R. Bull , T. Valentine , & T. Williamson (Eds.), Handbook of psychology of investigative interviewing: Current developments and future directions (pp. 35–52). Chichester: Wiley.
Wachi, T., Watanabe, K., Yokota, K., Otsuka, Y., Kuraishi, H., & Lamb, M. (2014). Police interviewing styles and confessions in Japan. Psychology, Crime & Law, 20, 673–694.
Wachi, T., Watanabe, K., Yokota, K., Otsuka, Y., & Lamb, M. E. (2016). Japanese suspect interviews, confessions, and related factors. Journal of Police and Criminal Psychology, 31, 217–227.
Walsh, D., & Bull, R. (2015). Interviewing suspects: Examining the association between skills, questioning, evidence disclosure, and interview outcomes. Psychology, Crime & Law, 21, 661–680.
Witt, J. W. (1973). Non-coercive interrogation and the administration of criminal justice: The impact of Miranda on police effectuality. The Journal of Criminal Law and Criminology, 64, 320–333.
NOTE
1 Methods of torture and lie detection techniques are not included in Kelly et al.’s (2013) taxonomy.
9 Detecting Deception
PÄR ANDERS GRANHAG AND MARIA HARTWIG
CHAPTER OUTLINE
9.1 INTRODUCTION
9.2 THEORETICAL APPROACHES TO DECEPTION 9.2.1 The Emotional Approach
9.2.2 The Cognitive Load Approach
9.2.3 The Self-Presentational Perspective
9.3 OBJECTIVE CUES TO DECEPTION
9.4 LIE-CATCHERS’ PERFORMANCE 9.4.1 Misconceptions about Deceptive Behaviour
9.4.2 Realism in Deception Detection Studies
9.5 DETECTING DECEPTION FROM VERBAL CONTENT 9.5.1 Statement Validity Analysis
9.5.2 Reality Monitoring
9.5.3 Scientific Content Analysis
9.6 COMPUTER-BASED LINGUISTIC ANALYSIS 9.6.1 Linguistic Inquiry and Word Count (LIWC)
9.6.2 Computer Analysis of Voice Stress
9.7 PSYCHO-PHYSIOLOGICAL DETECTION OF DECEPTION 9.7.1 Development of Psycho-Physiological Detection of Deception
9.7.2 The Control Question Test (CQT)
9.7.3 The Concealed Information Test
9.7.4 Countermeasures
9.8 STRATEGIC INTERVIEWING IN ORDER TO ELICIT AND ENHANCE CUES TO DECEPTION 9.8.1 The Cognitive Load Approach
9.8.2 The Unanticipated Questions Approach
9.8.3 The Verifiability Approach
9.9 NEW DIRECTIONS IN DECEPTION DETECTION RESEARCH 9.9.1 fMRI as a Deception Detection Tool
9.9.2 Discriminating Between True and False Intentions
9.10 TRAINING TO DETECT DECEPTION
9.11 CONCLUSIONS
9.12 SUMMARY
LEARNING OUTCOMES
BY THE END OF THIS CHAPTER, YOU SHOULD BE ABLE TO:
Understand why a psychological analysis of deception and its detection is important in a criminal investigation and in court
Appreciate the principal research methods used to explore the detection of deception
Understand the implications of existing findings within the field of deception detection.
9.1 INTRODUCTION
We are surrounded by deception. We all know only too well what it is means but, still, “deception” is not easy to define. The conceptualisations offered in the literature are many. For the present context we define deception as an act “intended to foster in another a belief or understanding which the deceiver considers to be false” (Zuckerman, DePaulo, & Rosenthal, 1981, p. 3). Thus, to unintentionally misremember is not to lie. Furthermore, distinctions can be made between falsifications (everything being told is contrary to the truth), distortions (the truth is altered) and concealment (the liar holds back the truth).
In the field of deception detection, the most frequently studied situation is when a person, frequently referred to as a target, provides a statement about the past that is either truthful or deceptive. An electronic recording, typically a short videotape of the statement, is then shown to observers, sometimes referred to as lie-catchers. The task of these lie-catchers is to make a judgment of whether the target is lying or telling the truth. For around half a century, researchers have relied on this method as the conventional way to study human deception detection. In this chapter we will provide an overview of the outcome of this traditional research, but we will also acknowledge a paradigm shift that has taken place within the field.
9.2 THEORETICAL APPROACHES TO DECEPTION
What cognitive and emotional processes can we expect to be at play during deception? And how might these processes cause liars’ behaviour to differ from truth tellers’? There are at least three theoretical perspectives that provide the basis for predictions about behavioural differences between liars and truth tellers: the emotional approach, the cognitive load approach and the self-presentational perspective (DePaulo & Morris, 2004; Bond, Levine, & Hartwig, 2015).
9.2.1 The Emotional Approach
The emotional approach states that lying causes emotions that differ from those experienced while telling the truth (Ekman, 2001). For example, a liar may experience fear of being judged as not being truthful, guilt about telling a lie, or perhaps even glee at the prospect of being able to fool someone – so-called “duping delight” (Frank & Svetieva, 2012). The consequences of being judged as a liar, and hence the fear of apprehension, may differ depending on the context. For example, being judged as deceptive when suspected of having committed a serious crime could have serious consequences, which can create a great deal of fear. According to the emotional approach, experiencing emotions when lying can lead to leakage of these emotions in the forms of expressions of emotion. For example, fear of detection may cause liars to experience stress and arousal, causing the pitch of voice to rise and increasing blushing, sweating and number of speech errors, while feelings of guilt will cause liars to avert their gaze. According to the emotional approach, the stronger the emotions experienced by the liars, the more likely that these emotions will leak, leaving visible traces in demeanour (Ekman, 2001; Porter, ten Brinke, & Wallace, 2012).
9.2.2 The Cognitive Load Approach
The cognitive load approach is based on the fundamental premise that lying may be more mentally demanding than telling the truth (Blandón-Gitlin, Fenn, Masip, J., & Yoo, 2014; Vrij, 2015a; Vrij et al., 2008). Lying can be a more difficult task than telling the truth, in that a liar must provide a story consistent with the facts known by the interviewer, detailed enough to appear based on something self-experienced, but simple enough to be remembered if one is asked to repeat the story later on (Burgoon, Buller, & Guerrero, 1995). The cognitive load approach predicts rather different patterns of behaviour than the emotional approach. The reader can easily picture the cues that may arise from cognitive load: imagine a person who is asked to solve an arithmetical problem in their heads, or to recite the alphabet backwards. This person’s speech is likely to be marred by speech disturbances and long pauses. Moreover, they might blink less frequently (Leal & Vrij, 2008), and the mental burden they are facing might lead to a general reduction in body movements, in particular in the form of movements of peripheral limbs (e.g. arms/hands and legs/feet). For a recent meta-analysis of this approach see Vrij, Fisher and Blank (2017).
9.2.3 The Self-Presentational Perspective
The emotio
nal and cognitive approaches both view lying as a process that differs in a fundamental respect from telling the truth. In contrast, the self-presentational perspective emphasises the similarities between truth tellers and liars (DePaulo et al., 2003), Self-presentation has been defined as regulating one’s own behaviour to create a particular impression on others (DePaulo, 1992). In the self-presentational view, liars and truth tellers share a mutual goal: to create an impression of honesty. Both are motivated to reach this goal and might invest effort in their attempts to reach it, and experience distress at the prospect of failure. The major difference between liars’ and truth tellers’ claims of honesty is that truth tellers have grounds for their claims and stay within the boundaries of the truth, whereas liars do not. DePaulo labels this the deception discrepancy: liars and truth tellers can be expected to differ cognitively and behaviourally in several important ways. As liars are aware that their claims to honesty are fake, they are less likely to embrace their accounts. This might lead them to impressions of ambivalence and tension. Their statements might also be less detailed and vaguer – partly because liars may lack familiarity with the domain they are describing, and partly to avoid being disproved. Echoing cognitive load theory, the self-presentational view of deception suggests that liars might experience more cognitive effort and show pronounced deliberation in what they say (DePaulo, LeMay, & Epstein, 1991). DePaulo and colleagues (2003) wrote: “Enthusiasm flows effortlessly from those who truly are experiencing enthusiasm, but fakers have to marshal theirs. Liars can be preoccupied with the task of reminding themselves to act the part that truth tellers are not just role-playing but living” (p. 78).
9.3 OBJECTIVE CUES TO DECEPTION
In order to empirically examine behavioural differences between liars and truth tellers – so-called “objective cues to deception” – DePaulo and colleagues conducted a comprehensive meta-analysis of the accumulated deception literature (DePaulo et al., 2003; see also DePaulo & Morris, 2004), including 1,338 estimates of 158 behaviours. The majority of the studies covered in the meta-analysis included college students as participants, and were carried out in laboratory settings, but there were also some studies of lies and truths told under real-life, high-stakes circumstances. The studies included people lying or telling the truth about personal opinions, about an event they had witnessed, and about mock transgressions (i.e. a mock crime).
The most important results from this meta-analysis were that (1) reliable cues to deception were scarce, and (2) behaviours that were actually related to deception lacked strong predictive value. The average effect size for cues to deception in DePaulo and colleague’s meta-analysis was d = .10, a difference that is barely noticeable to the naked eye. Liars appeared more tense than truth tellers, reflected in dilated pupils and heightened voice pitch. People without prior knowledge who were asked to rate the appearance of liars and truth tellers tended to perceive liars as more tense and nervous than truth tellers. Liars were also rated as less cooperative than truth tellers (but see Vrij, 2005b), and their faces were perceived as less pleasant.
There were a few indications that liars’ stories differed from those of truth tellers. Liars talked for a shorter time and include fewer details compared to truth tellers. Also, liars’ stories made less sense in that they were less plausible, less logically structured and more ambivalent. Liars also sounded more uncertain, and appeared less vocally and verbally immediate, meaning that observers perceived liars to be less direct, relevant and personal in their communication. There were some specific details that differed between deceptive and truthful accounts: truth tellers spontaneously corrected themselves more often and admitted not remembering more frequently than liars, indicating that liars’ stories may lack some of the so-called ordinary imperfections characteristic of truthful accounts (consistent with findings from research on statement validity analysis, described later in this chapter). Taken together, the self-presentational perspective, the cognitive load and the self-presentational approach all received some support from these results.
9.4 LIE-CATCHERS’ PERFORMANCE
There is a huge body of research investigating human deception detection accuracy. With few exceptions, accuracy levels fall between 45% and 60% (Vrij, 2008). A meta-analysis conducted by Bond & DePaulo (2006) reported an average accuracy level of 54%. Bearing in mind that the level of chance is 50%, this is hardly an impressive performance but, considering the scarcity and weakness of valid cues to deception, it is not too surprising (for a comprehensive discussion of lie detection accuracy, see Hartwig and Bond, 2011).
Presumed lie experts – such as police officers, judges and customs officers – have also participated in studies on deception detection. It might be assumed that these groups are more skilled at assessing veracity since they face this task in their working lives (Mann, Vrij, & Bull, 2004). Police officers themselves seem to believe that they are better lie detectors than the average person (Inbau, Reid, Buckley, & Jayne, 2001; Vrij, 2004). The studies conducted so far on police officers’ ability to detect deception provide little support for this notion (for an overview, see Vrij, 2005a). Accuracy rates tend to fall between 45–60%: very similar to those observed for lay people (but see Mann et al., 2004). More generally, there is little support for individual differences in deception detection ability (Bond & DePaulo, 2008). In sum, the finding that deception detection accuracy is mediocre is a robust phenomenon.
9.4.1 Misconceptions about Deceptive Behaviour
A common explanation for poor lie detection ability is that people harbour misconceptions about the characteristics of deceptive behaviour, and that they therefore rely on invalid cues when attempting to distinguish between truths and lies. This view has been labelled the wrong subjective cue hypothesis (Hartwig & Bond, 2011). Survey research of both lay people and presumed lie experts (e.g. police officers) has supported this hypothesis by showing a lack of overlap between objective cues to deception and the behaviours people believe are associated with deception (Hartwig & Granhag, 2015; Strömwall, Granhag, & Hartwig, 2004). For example, people frequently express the belief that liars are prone to gaze aversion (a decrease in eye contact). People also tend to associate lying with hesitations, slowed speech rate, longer and more frequent pauses, and an increase in smiling and self-manipulations, such as hand/finger and leg/foot movements (Vrij, 2008). Generally, these behaviours are indicative of nervousness rather than lying, and liars are not necessarily more nervous than truth tellers (Köhnken, 1989, quoted in Vrij & Semin 1996).
PHOTO 9.1 People tend to associate lying with an increase in smiling and self-manipulations, such as hand/finger and leg/foot movements.
Source: © Nadya Lukic/iStockphoto
9.4.2 Realism in Deception Detection Studies
The external validity of deception detection research has been questioned. The most important and persistent criticism has concerned two aspects: first, the realism in the target material (i.e. the lies and truths); and second, the realism of the situation in which the lie-catchers are put (Hartwig, 2011). The targets in the standard deception detection experiment provide either a truthful or a deceptive statement regarding their opinions, emotions or involvement in some past event (sometimes a mock crime). This could be characterised as a low-stakes situation, in that failing to give a credible impression has little or no consequences. This does not mirror the high-stakes situations encountered in the legal system, for example when a suspect is assessed in order to determine the likelihood of guilt. Failing to act in a credible way in such a situation can have severe and far-reaching consequences. It has been argued that deceptive behaviour may be different in low- and high-stake situations and that it thus would be premature to draw conclusions about, for example, police officers’ ability to detect high-stake lies based on laboratory experiments (Miller & Stiff, 1993). Aldert Vrij and his colleagues have taken an important step in investigating real-high-stake lies and truths in a police interrogation (e.g., Mann et al., 2004). Although th
e pattern is not entirely clear, based on these studies it seems that realistic target materials might slightly improve people’s ability to detect lies. Below, we will discuss whether this holds true when inspecting the entire literature using meta-analytic methods.
The second part of the criticism of the realism in deception detection studies concerns the context in which the assessment occurs. In the typical study, participants watch a video-clip of the target. Hence, they are restricted to passively watching the suspects, without any background information, and without the possibility to ask questions as they find necessary in order to form the basis for a veracity assessment (Hartwig, Granhag, Strömwall, & Vrij, 2004). This is very different from the situation in which police officers normally make judgments of veracity. Instead, they often make judgments on the basis of their background information, and on their own interaction with the suspect. It could be argued that one reason for the modest accuracy rates often found in studies on police officers’ deception detection ability is that they are unfamiliar with catching lies from passive observation. Research has disproven this notion. For example, it has been shown that experienced criminal investigators fail to accurately assess veracity even when getting the chance to plan and conduct an interrogation in the manner of their own choice (Hartwig et al., 2004).
Hartwig & Bond (2011) conducted a meta-analysis examining the concern about limited generalisability of laboratory results – more specifically, the extent to which weakness in cues to deception are robust across situations. This meta-analysis aimed to establish whether it was the case, as some critics of laboratory research have argued (Buckley, 2012; O’Sullivan, Frank, Hurley, & Tiwana, 2009), that lies become more apparent as the conditions approach real-life forensic settings. The researchers investigated whether lies were more detectable when they were accompanied by strong emotion; when the stakes were high; when they were told outside the laboratory as opposed to within it; and whether it made a difference if participants were instructed to lie versus deciding to lie themselves. The meta-analysis did not support the claim that weakness of cues to deception is a laboratory artefact: results showed that the detectability of lies was stable across laboratory and field settings and provided no support for the view that the laboratory produces unrealistic results with little bearing on real-life settings (e.g., Buckley, 2012).