Lecture 4: Detecting Deception

Question 1

Define deception.

Answer 1

An act intended to foster in another person a belief or understanding which the deceiver considers to be false

Question 2

What are the 3 kinds of deception?

Answer 2

1. Falsification: everything being told is contrary to the truth
2. Distortion: the truth is altered to fit the liar’s goal
3. Concealments: the liar holds back the truth

Question 3

Describe the emotional approach to lie detection by Ekman (2001).

Answer 3

• Premise: lying causes emotion that differ from those experienced while telling the truth
  
  • e.g. may feel fear of being judged as not being truthful
  • May differ based on context
• Experiencing emotions when lying can have behavioural consequences
  
  • Fear of apprehension causes the experience of stress and arousal
• Resulting in: higher voice pitch, increased blushing, sweating, speech errors, + guilt causes you to avert your gaze
• Leakage hypothesis: The stronger the emotions experienced by the liars, the more likely that these emotions will “leak”, leaving visible traces in demeanour

Question 4

What are the problems with the emotional approach?

Answer 4

• Innocent + guilty suspects might both experience fear of repercussions

Physiological arousal symptoms don’t necessarily indicate guilt; we don’t have any baseline to compare to

• What about cultural differences? e.g. In some cultures you just aren’t supposed to have a lot of eye contact
• What if the person just naturally sweats or blushes a lot?
• What about an innocent person who’s just been roughed up? Wouldn’t they still be physiologically aroused?
• What if you’re a really good criminal and don’t demonstrate any of these symptoms?

Question 5

Describe the cognitive load approach to lie detection by Vrij et al. (2008).

Answer 5

• Premise: lying is more cognitively demanding than telling the truth
  
  • Have to provide a consistent story
  • Detailed enough to appear based on something self-experienced
  • But simple enough to be remembered
• Research shows that cognitively demanding tasks can result in:
  
  • Gaze aversion (it can be distracting to look at the conversation partner)
  • Fewer body movements
  • Long pauses

Question 6

What are the problems with the cognitive load approach?

Answer 6

• What is the baseline? What if you’re someone who just takes a long time to react to things?
  
  • If you’re innocent + being accused you’ll probably be confused + blank on the answer since you don’t know
• What determines the degree of acceptable inconsistency?
  
  • Rarely can people provide the same story every time

Question 7

Describe the attempted control approach to lie detection by Vrij (2004).

Answer 7

• Premise: Liars may be aware that internal processes could result in cues to deception, so they try to minimize these cues
• Ironically, this sometimes leads to overcompensation…
  
  • → creating different cues to deception (like creating an overly stiff impression)

Question 8

What are the problems with the attempted control approach?

Answer 8

• Assuming that the assumptions from the other 2 approaches are a correct baseline
• Inherent contradiction: Is it gaze aversion or overcompensation?
• Logically impossible to determine—how does the investigator know that the suspect knows they know they’re lying?

Question 9

What have meta-analyses of the 3 approaches to lie detection found?

Answer 9

Overall findings are that: A) reliable cues to deception are scarce; B) behaviours that are actually related to deception lack strong predictive value

• Liars seem to be somewhat more tense than truth-tellers
  
  • Pupils more dilated
  • Pitch of voice is higher
  • Appearance more tense and nervous
  • Less cooperative
  • Faces perceived as less pleasant
• Stories: Liars talk for a shorter time + include fewer details
  
  • Sound more uncertain—less direct, relevant, and personal
  • But what if you’re just a really concise story-teller?
  • Stories make less sense—less plausible, less logically structured, and more ambivalent
    
    • This one can actually be helpful in certain contexts but still can’t reliably predict guilt
• Details: Liars spontaneously correct themselves
  
  • Admit not remembering to lesser extent
  • Therefore lacking normal imperfections of truthful accounts

But again, what’s the baseline? These aren’t very helpful

Question 10

How good are people at detecting lying?

Answer 10

• With few exceptions, accuracy levels fall between 45-60% (basically chance)
  
  • In meta-analysis, average accuracy is 54%
• Okay, that’s fine, but what about trained lie experts? Police officers, judges, customs officers?
  
  • They have experience + believe they’re better than the average person
  • Accuracy levels still fall between 45-60%

Question 11

What factors influence how good police officers may be at lie detection?

Answer 11

1. Their training tells them to focus on all kinds of verbal + nonverbal cues, which may not necessarily indicate lying
2. Cultural differences + stereotype threat: the anxiety or concern a person experiences when he or she is at risk of confirming a negative stereotype about their social group
3. confirmation bias: “once we form a strong belief about someone, we tend to seek out information that confirms that belief and to simultaneously dismiss information that contradicts that belief”
   
   • Dangerous Decisions Theory (DDT): “decision makers’ (investigators, judges, and jurors) initial judgments of credibility, often driven by irrational cues, can potentially bias subsequent information heard”

Studies have shown that police trained to not be as enthusiastic or confident about their abilities tend to make slightly less mistakes

Question 12

What are the general misconceptions about lie detection?

Answer 12

• There are wrong beliefs about the characteristics of deceptive behaviour
  
  • There is a lack of overlap between objective (actual cues) and subjective cues (what we think is associated w/ deception)
• Gaze aversion, hesitations, slower speech rates, longer and more frequent pauses, increase in smiling and hand/finger and leg/foot movements are highly correlated with … nervousness
  
  • In addition, studies show that liars aren’t necessarily more nervous than truth-tellers

Question 13

Explain Kassin & Fong’s (1999) study looking at the usefulness of the Reid Manual on lie detection.

Answer 13

• Randomly assigned Ps to control or to receive training in catching deception with the Reid Manual
• Group who received training were more confident + had more reasons/justifications for their judgments
• Controls had an accuracy level of 56% (not too much better than chance)
• Trainees had an accuracy level of 46% (even worse! And much lower than 80%)
• Exposure to and use of the cues recommended is not only inefficient, but directly counterproductive in improving accuracy in detecting deception and truth
  
  • Losing both opportunity cost (the opportunity to have chosen the better option) + direct harm (condemning even more innocent people)
• 500,000 people working in law enforcement and other agencies, as well as private companies, have been trained in the technique
  
  • The Reid Manual claims 80% accuracy in their advertising, but there are no studies to back this up

Question 14

Describe the statement validity analysis method of lie detection.

Answer 14

• Most widely used technique based on verbal content
• Premise: if a statement is based on the memory of an actual experience, it will differ in content and quality from a statement based on fabrication

Four stage procedure:

• 1) Thorough analysis of the case-file (regular proper police procedure)
• 2) Semi-structured interview based on information gleaned from evidence (audio-taped and transcribed)
  
  • (Basically Cognitive Interview Enhanced for suspects)
• 3) Criteria-based content analysis (CBCA)—19 criteria grouped into 5 basic categories
  
  • These criteria are based on sensation + logic of thoughts
• 4) Validity Checklist—The presence of each of the 19 criteria is rated
  
  • 0 = absent → 1 = present → 2 = strongly present
• The more criteria present and the stronger the presence of each criterion, the stronger the support for the hypothesis that the statement is based on genuine personal experience
• Not necessarily a lie detector but a truth detector

Question 15

Describe the reality monitoring method of lie detection.

Answer 15

• reality monitoring: the process by which people distinguish memories of real events from memories of imagined events
• Premise: real memories are products of perceptual and contextual processes, whereas imagined are products of cognitive information
  
  • Perceptual (e.g. taste, touch, smells) + contextual (e.g. spatial, temporal)
  • Cognitive information; e.g. “I must have been tired because it was late”
• If RM works for distinguishing one’s own real and imagined events, perhaps it can be used to distinguish other people’s real and imagined events
  
  • Can help uncover truthful vs. deceptive accounts for example (suspects)
  • Or perhaps even misinformation (eyewitnesses)

Question 16

What is the usefulness of both statement validity analysis (CBCA) and reality monitoring?

Answer 16

• CBCA: In a review of 37 studies (from laboratory settings)
  
  • Overall accuracy of 73%
  • And, proved equally good for detecting both truthful + fabricated accounts
• Reality monitoring: literature shows the overall accuracy rate to be 75%
  
  • And equally accurate in detecting truths and lies
  • So not too different from the CBCA technique
• The RM technique could be an interesting complement (or alternative) to CBCA
  
  • As it’s based on a well-established theoretical framework
  • And it’s easy to learn and use
  • Perhaps will yield similar or different results than CBCA
• Both are basically the same thing as a CIE, except they’re criteria for evaluating the interview (if it’s done properly)

Question 17

What is a polygraph and how is it used in Canada?

Answer 17

• Measures and records several physiological indices: blood pressure, pulse, respiration, skin conductivity
  
  • The subject is asked and answers a series of questions
  • Premise: deceptive answers will produce physiological responses that can be differentiated from non-deceptive
• R. v. Béland (1987): Supreme Court of Canada rejected the use of polygraph results as evidence in court
  
  • This decision did not, however, affect the use of the polygraph in criminal investigations + it continues to be used as an investigative tool
• In Canada, the polygraph is regularly used as a forensic tool in: 1) the investigation of criminal acts, 2) the screening of employees for government organizations (sometimes)

Question 18

What is the relevant-irrelevant test (RIT)?

Answer 18

• Premise: “the crime-relevant questions should be especially arousing for the person who actually committed the crime”
  
  • Examiner looks at: “the difference in the strength of the physiological response of the suspect to the two types of questions”
• Problem: “innocent suspects, who would likely feel threatened by the questioning and its purpose, might also find the crime-relevant questions arousing”

Question 19

What is the control question test (CQT) and what are the steps involved in using it?

Answer 19

• control question test: A method of polygraph testing that compares reactions to control questions concerning past transgressions to questions relevant to the crime under investigation
  
  • Premise: A guilty person should react more strongly to the relevant questions

Types of questions:

• “Irrelevant” control questions: should cause no discomfort (e.g. “Is your name Will?”)
• “Probable-lie” control questions “involve behaviours that are uncomfortable for suspects but not directly related to the crime under investigation,” that most people will lie about (e.g. “Have you ever taken something that didn’t belong to you?”)
• “Relevant questions” concerning the crime

Steps to the CQT:

• 1) Start with rapport building + get basic information
• 2) Questions are formulated and the subject and examiner discuss the questions—i.e. the suspect knows what the questions are
• 3) Then the tester will explain how the polygraph works, emphasizing that it can detect lies and that it is important to answer truthfully
  
  • “stim test”: the subject is asked to deliberately lie and then the tester reports that he was able to detect this lie
• 4) Now run the question phase several times and average answers (suspect knows they’ll be asked several times).
  
  • Why? Want to make sure that the one time wasn’t just an anomaly
• You pass if the relevant questions are lower than the probable-lie
• The CQT is quite good at classifying guilty subjects
  
  • Studies show an accuracy rate ranging from 80-91%
• Problems:
  
  • 1) There is a tendency for false positives (finding an innocent person guilty)
  • 2) The CQT may be vulnerable to being conducted in an interrogation-like fashion

Question 20

What are the 6 weaknesses of polygraphing techniques?

Answer 20

1. “some people are so emotionally nonreactive (e.g., psychopathic or fearless or controlled) that lying produces little physiological response”
2. “there is no guarantee that innocent people will not react strongly to questions about whether they committed a crime”
3. “if people do not have faith in the validity of the polygraph, they may not respond in the way examiners suppose”
   
   • Related problem: difficult to convince people of the infallibility of the polygraph + sometimes using trickery to do so
4. Standardization—all examiners ask different Qs, have different demeanours, approaches, + interpretations
   
   • Even more subjectivity in the scoring—what’s the difference between a “mild” or “dramatic” difference in reaction?
5. countermeasures: techniques for thwarting the polygraph, usually to “elevate arousal during control questions or suppress arousal during relevant questions”; e.g. biting your tongue, pressing your toes to the floor
6. Ethical considerations—using extremely uncomfortable personal info about someone’s past to take baseline readings

Question 21

What is the guilty knowledge test (GKT) and what are some problems with it?

Answer 21

• guilty knowledge test (GKT): “to detect whether or not someone knows facts only a criminal would know”; “recognition will be reflected in elevated physiological arousal”
• unscored buffer: The first item in a test is thrown out b/c people tend to react strongly to it anyways
• Usually give 6 options, all options should be equally likely to innocent suspects

Problems:

• 1) Requires criminal remembering many details of the crime
  
  • Maybe not paying attention to what the victim’s wearing
  • Or memories from other crimes pop in + interfere
• 2) Needs enough crime-related facts for the GKT Qs to be constructed
• 3) Facts need to not be widely publicized so that only the actual perpetrator would know these details

Question 22

What is the guilty actions test (GAT) and what are some problems with it?

Answer 22

• guilty actions test (GAT): similar to the GKT, but frames questions in terms of actions vs. knowledge (e.g. “You murdered them in a house? Bank? Store?”)
• Permits “an innocent suspect, even with knowledge of the case facts, to respond with a no to the critical question”
• “the GAT significantly reduced the false-positive rates [vs. GKT], although these rates were still very high (50%)”

Problems:

• Many witnesses or accomplices to a crime would know many of these details, but only one person actually committed a crime
• Relies on the skill of the polygraph administrator to come up w/ good questions

Question 23

How are fMRIs used in lie detection and what are some drawbacks?

Answer 23

• fMRIs measure activity of the brain through oxygen, through taking several photos they are stitched together to create a moving image of the brain
• Experiments show that some regions of the brain are more active than others when people tell a lie
• Spontaneous lies vs. rehearsed lies also tend to generate different patterns of brain activity

There are several limitations to use fMRI:

• 1) Not portable, expensive, requires subject to lay motionless + silent
• 2) Can only take a snapshot every 2 seconds
• 3) Pushing a “yes/no” button in an experiment is very different from high-consequence lying
• 4) These experiments have only examined 10-20 people
• 5) Admissibility; would essentially be the same as polygraphs

Question 24

How are EEGs used in lie detection and what is its limitation?

Answer 24

• Premise: “the brain has a typical pattern of electrical activity that is associated with the retrieval of things that we remember”
• Doesn’t speak to the truth of statements but rather suspect’s familiarity w/ the objects that they’re presented
• “The inferences to be drawn from these results are in the hands of the jury.
  
  • Thus, should this technique ever meet the expectations of the judicial and legal systems, its admission is unlikely to face the same challenges as the fMRI”
• EEGs are faster + can tell where the responses are coming from
  
  • Studies show that certain brain waves react in order to suppress the intent to tell a truthful response and replace it w/ a lie

Problems:

• Same limitations as the GKT (i.e. witnesses + people who’ve been exposed to it on the news can have recognition)
• Biggest problem: “The statistical method used to analyze the EEG data is kept secret, so other researchers cannot independently evaluate its validity”

Question 25

What are two basic problems with physical lie-detection technologies?

Answer 25

• 1) cognitive privacy: “Should our thoughts—even our deceptive ones—be beyond the reach of the law?”
• 2) We’ve developed better + better technology to detect minor physiological changes, but “the enduring problem is that there appears to be no distinctive set of physiological responses exclusively associated with lying”
  
  • “if there is no clear signal to detect, these advances cannot produce a fully trustworthy method of detecting lies”