Copyright © 2012 Pearson Canada Inc Chapter 4 Deception

Copyright © 2012 Pearson Canada Inc Learning Objectives Describe the two types of polygraph tests Describe the most common errors made by the Comparison Question Test (CQT) and Concealed Information Test (CIT) Describe physiologically based alternatives to the polygraph Outline the verbal and non-verbal cues of deception

Copyright © 2012 Pearson Canada Inc Learning Objectives Define malingering, and list the three explanatory models of malingering Differentiate between the types of studies used to examine malingering

Copyright © 2012 Pearson Canada Inc Polygraph Method Based on the belief that deception is related to physiological change Measures: – Respiration – Heart rate – Sweating

Copyright © 2012 Pearson Canada Inc Uses of Polygraph Helps in criminal investigations (suspect is asked to take a polygraph test) Verify a crime has occurred (victim is asked to take a polygraph test) Monitoring sexual offenders on probation (United States) Pre-employment screening for security agencies and police

Copyright © 2012 Pearson Canada Inc Types of Polygraph Tests There are two main types of polygraph tests: – Comparison Question Test (CQT) – Concealed Information Test (CIT)

Copyright © 2012 Pearson Canada Inc Comparison Question Test Includes three types of questions: –Irrelevant –Relevant –Comparison Deception is assessed by comparing physiological responses between relevant and comparison questions

Copyright © 2012 Pearson Canada Inc Comparison Question Test: Sample Questions QuestionPurposeExample IrrelevantUsed to obtain a baseline. Are you left handed? RelevantDeal with the crime. Did you assault Sam Smith on March 11 th ? ComparisonDeal with prior antisocial behaviour. Before age 25, did you ever verbally threaten to hurt anyone?

Copyright © 2012 Pearson Canada Inc Phases of the CQT Pre-test interview: Interview with suspect to develop the comparison questions Polygraph exam: Questions are asked while suspect’s physiological responses are measured Scoring: Polygraph examiner scores the physiological responses to determine if the suspect is truthful, deceptive, or inconclusive Post-test interview: If a suspect is judged deceptive they are pressured to confess

Copyright © 2012 Pearson Canada Inc Control Question Test: Assumptions Assumes guilty people react more to relevant questions and innocent people react more to comparison questions Suspect falsely accused of a crime might react more strongly to questions about the crime than to vague questions concerning past behaviour

Copyright © 2012 Pearson Canada Inc Concealed Information Test Assesses if suspect has information that only the criminal would know Asks suspects multiple-choice questions, one option is correct Assumes if the suspect is guilty they will react strongly to correct information Rarely used in Canada or United States

Copyright © 2012 Pearson Canada Inc Types of Polygraph Studies Laboratory studies – Ground truth is known – Limited application to real-life situations Field studies – Real-life situations and actual suspects – Ground truth is not known

Copyright © 2012 Pearson Canada Inc Accuracy of the CQT Majority of guilty suspects correctly identified – 84% to 92% guilty correctly identified Relatively large number of innocent suspects falsely identified as guilty – 9% to 24% false positive errors Accuracy of original examiners higher than blind scorers

Copyright © 2012 Pearson Canada Inc Accuracy of CIT No field studies have been conducted in North America Very accurate at identifying innocent participants – Around 95% correctly identified Less accurate at identifying guilty participants – Around 85% correctly identified

Copyright © 2012 Pearson Canada Inc Countermeasures Both physical and mental countermeasures dramatically reduce the effectiveness of the CQT (Honts et al., 1994) The CIT does not appear to be effected by anti-anxiety drugs (Iacono et al., 1992)

Copyright © 2012 Pearson Canada Inc Admissibility of Polygraph Did not pass general acceptance test when first admitted as evidence in court (Frye v. United States, 1923) Currently allowed in some States if agreed by both prosecution and defence Not admissible into evidence in Canadian courts (R. v. Beland, 1987)

Copyright © 2012 Pearson Canada Inc Other Measures Thermal imaging: – Detects facial warming due to blood flow Event-related brain potentials (ERP) –Electrodes measure brain activity in response to a significant stimulus –P300 used to detect guilty knowledge

Copyright © 2012 Pearson Canada Inc Other Measures: fMRI Functional magnetic resonance imaging (fMRI) – Measures differences in brain activity when people are being honest versus deceptive – Different parts of the brain are activated when person is deceptive versus when they are telling the truth

Copyright © 2012 Pearson Canada Inc Detecting Deception: Verbal Cues Verbal cues most consistently related to deception include: – Higher voice pitch – Increased speech disturbance (ah, umm) – Slower speech Pattern of verbal cues may depend on how cognitively complex the lie is

Copyright © 2012 Pearson Canada Inc Verbal Characteristics of Deception (Table 4.3) Speech fillers – Frequency of saying “ah” or “umm” Speech errors – Repetition, change, slips of tongue Pitch of voice Rate of speech Speech pauses

Copyright © 2012 Pearson Canada Inc Non-verbal Characteristics of Deception (Table 4.3) Gaze aversion Smiling Blinking Fidgeting Illustrators Hand or finger movements Leg or foot movements Body movements Shrugs Head movements Shifting positions

Copyright © 2012 Pearson Canada Inc Detecting Deception: Verbal Cues Verbal cues that are indicative of honesty: – Make corrections in account – Admit to lack of memory Verbal cues that are indicative of deception: – Little detail – Less compelling accounts – More nervous and tense

Copyright © 2012 Pearson Canada Inc Detecting Deception: Professionals Vrij (2000) reported accuracy rates: – Truths = 67% – Lies = 44% Accuracy of professional lie catchers vary: – Have a truthfulness bias – Tend to rely on wrong cues

Copyright © 2012 Pearson Canada Inc Factitious Disorder Intentionally produced physical or psychological symptoms Internal motivation to assume the sick role Absence of external incentives

Copyright © 2012 Pearson Canada Inc Somatoform Disorder Physical symptoms that cannot be explained by organic impairment Symptoms are not intentionally produced Often co-occurs with depression or anxiety

Copyright © 2012 Pearson Canada Inc Malingering Psychological or physical symptoms are voluntary There are external motivations for the production of symptoms – Malinger mental illness to avoid criminal punishment, to obtain drugs, or for compensation such as disability – Prevalence quite high in forensic settings

Copyright © 2012 Pearson Canada Inc Defensiveness Defensiveness refers to the conscious denial or minimization of physical or psychological symptoms – Might wish to appear high functioning to be seen as a fit parent – Some patients may not want to admit they certain symptoms Copyright © 2012 Pearson Canada Inc. 27

Copyright © 2012 Pearson Canada Inc Explanations of Malingering Three explanatory models of malingering (Rogers, 1990): – Pathogenic model – Criminological model – Adaptational model

Copyright © 2012 Pearson Canada Inc Pathogenic Model Assumes malingering results from an underlying mental disorder The patient attempts to gain control over his or her pathology by creating fictitious symptoms Little empirical support

Copyright © 2012 Pearson Canada Inc Criminological Model Malingering due to: – Antisocial personality disorder (APD) – Forensic assessment – Lack of cooperation – Discrepancy between findings Research does not support an association between APD or cooperation and malingering

Copyright © 2012 Pearson Canada Inc Adaptational Model Asserts malingering is likely to occur when: – A perceived adversarial context is present – Personal stakes are very high – No other viable alternatives are perceived Research findings support this model

Copyright © 2012 Pearson Canada Inc Research Assessing Malingering Three basic designs: – Case study – Simulation – Known groups

Copyright © 2012 Pearson Canada Inc Case Studies Useful for generating a wide variety of hypotheses Only way to study rare syndromes

Copyright © 2012 Pearson Canada Inc Simulation Design Most frequently used Participants are told to malinger a specific disorder and compared to –Control group –Clinical comparison group High experimental rigour Limited generalizability to the real world

Copyright © 2012 Pearson Canada Inc Known-Groups Design Involves two stages: – Establishing the criterion groups (e.g. genuine patients and malingers) – Analysis of the similarities and differences between criterion groups Good generalizability to real-world settings Problems classifying criterion groups

Copyright © 2012 Pearson Canada Inc Detecting Malingered Psychosis Clues regarding the symptoms: –Report rare, atypical symptoms, or absurd symptoms –Report atypical delusions or hallucinations –Absence of subtle symptoms –Continuous hallucinations rather than intermittent (continued)

Copyright © 2012 Pearson Canada Inc Detecting Malingered Psychosis (continued) Other clues: – Accuse clinician of not believing them – Presence of accomplice – Crime fits pattern of criminal history

Copyright © 2012 Pearson Canada Inc Assessments: SIRS The Structured Interview of Reported Symptoms (SIRS; Rogers et al., 1992) – Uses a structured interview – 172 items organized into 8 scales – Research indicates good validity

Copyright © 2012 Pearson Canada Inc Assessments: M-FAST The M-FAST test (Miller, 2000) –Interview-based method –25 items organized into 9 scales –Useful and reliable screening test for malingering

Copyright © 2012 Pearson Canada Inc Assessments: MMPI/MMPI-2 MMPI/MMPI-2 are self-report personality inventories – They contain scales such as the infrequency (F) scale and the Back F (F B ) scale selected to detect unusual or atypical symptoms – Research indicates these scales are the most useful at detecting malingerers (Rogers et al., 2003)