Exam 2 Flashcards
Deception Detection (An Overview)
› Why do people lie?
o Be familiar with and able to provide an original example of each of the 4 different types of lies
-its an adaptive behavior; it is also a way to protect ourselves or others
-commission
-omission
-antisocial
-prosocial
Commission
saying things that are not true
Omission
leaving details out that are true/
important
Omission: leaving out details (denials, partial
admissions of guilt)
Antisocial
lie that protects or benefits oneself; increase or preserve reputation
Prosocial
lie to protect/ benefit others
What is the theory underlying this method of lie detection? That is, why do we think that humans should be able to detect lies by observing other people?
-deception detection
Are lay people good lie detectors? Why or why not?
No, lay people are better at detecting the truth; they rely on truth bias, however, they are only a little above chance at detecting deception.
Are police good lie detectors? Why or why not?
No, they are also only above chance at detecting deception, however they rely more on the lie bias, the idea that most people are lying.
More Confident
Compare the accuracy of lay people vs. police at detecting lies. Who do we think should be better? Why? Who is better?
o If police aren’t better than lay people, be sure that you are able to discuss why they aren’t better.
-Police because they are trained to detect deception
-Neither, both police and lay people are only above chance at detecting deception
Police not better than chance BUT more confident
• Why?
– Police are trained to detect deception using cues that
are not indicative of lying!
– Liar’s stereotype: avert gaze, squirm, stutter, touch
themselves
How well are CRIM 157 students able to detect deception (on the basis of the speed lying activity completed in class)? Compare your performance to the typical performance of police and lay people.
Prison inmates gave true and false
confessions on video
• Police detectives and college students
judged the truthfulness of the confessions
• Who does better?
– College student accuracy: 59%
– Police accuracy: 48%
• Police demonstrated a bias toward lies
– This biased increased with interrogation training
and job experience
Why are humans so bad at detecting deception? (Hint: We discussed 3 reasons)
Flawed interpretation of verbal and non-verbal
behavior
– Lack of feedback on accuracy of detection
techniques
– Confirmation bias
* Seeking & interpret confirming evidence of guilt while
ignoring plausible explanations (general nervousness)
What is the liar’s stereotype? Does this stereotype outline useful cues to use when trying to determine whether or not someone is lying? Why or why not? If the liar’s stereotype does not outline useful cues, what cues can/should we use (according to research), if any?
Behavioral indicators that
interrogators are told to focus on
are flawed indicators of deception
• Large international survey (n = 2500) found that 70%
of people believe liars avert their gaze, squirm, touch
their bodies more, and stutter when lying (Bond &
DePaulo, 2008)
• Confirmation bias
– When we form a strong opinion about someone, we seek
out information that confirms that belief and dismiss
information that contradicts that belief
What is confirmation bias? How is this related to deception detection?
– When we form a strong opinion about someone, we seek out information that confirms that belief and dismiss information that contradicts that belief
-we already have a set response towards someone else (lying or not lying) and that decision will weigh which type of evidence we will pay attention to and which evidence we will ignore, this can lead to false accusations
don’t consider all information/ evidence provided
What is the typical paradigm used in research to assess deception detection abilities?
The polygraph
What are limitations of lab research on detecting deception?
Lab Studies
• Know ground truth
• Low-stakes lies
• (i.e. write an essay
as punishment, or
more extra credit
as reward)
• Inexperienced liars
• (i.e. college
students)
Real World
• Don’t know truth
• Even if convicted
• High-stakes lies
• (i.e. prison time)
• Experienced liars
• (i.e. criminals)
One of the assumed reasons for the relatively poor unaided detection rate is that people have the tendency to believe— rather than disbelieve— information that is being presented (i.e., the “truth bias” or ‘truth-default,” McCornack and Parks, 1986; O’Sullivan, 2003; Levine, 2014). As a result, they often (mis)take a lie for truth. The Truth-Default Theory posits that as most communication is honest most of the time, the benefits of believing outweigh the costs of occasional deception (Levine, 2014; Clare and Levine, 2019). Consequently, people can detect truths with greater accuracy than lies (the veracity effect; e.g., Levine et al., 1999). If too much trust stands in the way of deception detection, wouldn’t being distrusted be the antidote for such gullibility?
Alternative deception detection approaches
Polygraph
Criterion based content analysis
fMRI
EEG
Infrared thermal imaging
Laser doppler vibrometry
Computer voice stress analysis test (CVSA)
What is the theory underlying this method of lie detection? That is, why do we think that the polygraph, a machine, should be able to detect lies? What does the polygraph measure in order to detect lies?
-Lying will cause physiological changes
- Measures: Heart beats faster, breath quicker, blood pressure increases, skin moisture
What are some of the weaknesses or limitations associated with using the polygraph to detect deception? (Hint: There are 6)
-emotionally non-reactive people
-no guarantee that innocent people won’t react strongly to questions about a crime
-convince suspect the polygraph is flawless
-lack of standardization
-use of countermeasures
-ethical grounds (personal questions)
o Research on the polygraph
* How accurate is the polygraph at detecting liars and truth tellers in the lab? In the field?
They claim high accuracy rates
– Test 100 people, 4 incorrectly classified but
96 correct = 96% accuracy rate
* Laboratory studies
– Mock crime, ½ commit crime, all deny
– Strength = ground truth known
* Field studies with actual suspects
– Strength = realism and high arousal
– Weakness = criterion of accuracy is subjective
– Criterion-Based Content Analysis
o What is the theory underlying this method of lie detection?
Analysis of written statements
o What is used/analyzed to determine whether someone is lying or telling the truth?
truthfulness assessment through systematic analysis of written statements
Assess truthfulness of a descriptive event
– Used to assess child truthfulness in CSA
o What results would indicate that someone is lying? What results would indicate that someone is telling the truth?
Rate strength of statements based on
criteria
– Logical structure
– Amount of detail
– Context (space and time)
– fMRI
o What is the theory underlying this method of lie detection?
Lies in the Brain:
fMRI
* Detects “where” lying occurs
o What is used/analyzed to determine whether someone is lying or telling the truth?
– Pre-frontal cortex and parietal
cortex = cognitive work
Detects differences between
rehearsed and spontaneous
lies
– Spontaneous – areas
associated with visual imagery
– Rehearsed – episodic memories
o What are the limitations of this approach to deception detection?
– Expensive, not portable, requires
cooperation
– Large individual brain differences
– No clear brain regions associated with truth
telling
– EEG
o What is the theory underlying this method of lie detection?
-detects “when” lying occurs
o What is used/analyzed to determine whether someone is lying or telling the truth?
– Records neural impulses continuously
– Records event-related potentials (ERP’s)
* Research
– Respond to statements that are true or false
– Changes in brain waves detected
* Intent to suppress true response and replace with lie
* Brain fingerprinting = GKT with brain waves
Lying will cause arousal and warming around the eyes
-detects when lying occurs
-records neural impulses continuously
– Computer Voice Stress Analysis Test (CVSA)
o What is the theory underlying this method of lie detection?
Same underlying principle as polygraph
– Deception à anxiety à physiological symptoms
o What is used/analyzed to determine whether someone is lying or telling the truth?
Accuracy rates similar to polygraph
* Same underlying principle as polygraph
– Deception à anxiety à physiological symptoms
* Fluctuations(micro-tremors) in voice
– Pitch rises under stress
– Inaudible changes
* Much simpler to administer than
– Compare and contrast the ability of technology to detect deceit as compared to humans as lie detectors.
technology has more of an advantage at detection deceit (deception) due to all the little cues in the body that trigger a uncomfortable response, hinting at a lie. However, they all have their own flaws and can be manipulated
Pitfalls and Opportunities in Nonverbal and Verbal Lie Detection
› Why should we expect differences between liars and truth tellers? Which of these approaches has traditionally been the assumption methods of lie detection have relied upon? Which of these approaches do the authors of this article propose we should rely upon
-liars and truth tellers experience different emotions
-The polygraph
-Encouraging interviewers to say more SUE
Liars:
a) May experience stronger emotions (i.e. fear,
nervousness) as a result of their deception
b) May experience higher levels of cognitive load
c) Are inclined to use more and different strategies
to make a convincing impression on others
– What is the Ostrich Effect? How does this effect explain poor deception detection abilities/accuracy?
- Lies remain undetected because people do not
attempt to uncover the truth - “Ignorance is bliss”
we don’t pay attention to the evidence, we do not try to uncover the truth.
confirmation bias
– Even when people are motivated to detect deception, it’s still a difficult task. Why? (Hint: We discussed 7 reasons. Know and be able to discuss each of these and how and why they make lie detection difficult.)
*No nonverbal and/or verbal cues
uniquely related to deceit
* Ex. gaze aversion – what else could
it mean?
* 75% of cues we think are related
to deception are NOT
* Ex. gaze aversion, posture shifts,
pauses, self-references
Detection difficulty 2
- For behavioral cues that do exist, differences
between liars and truth tellers are small - 28% (14 cues) related to deception
- Ex. Fewer details, less plausible answers, fewer illustrators (i.e.
hand movements) - Cues to deceit generally unreliable and faint
Detection difficulty 3
Countermeasures
* Liars often deliberately attempt to appear credible to
avoid detection
* Do opposite of what they believe are lying behaviors
* Ex. Most people think liars look away, so …?
Detection difficulty 4
Embedded Lies
* Lies are often embedded in truths
* Ex. What did you do Tuesday night?
* Give details of what you really did on Monday night
Detection Difficulty 5
No Adequate Feedback
* Lie Detectors do not
receive adequate
feedback about their
judgments
* Cannot learn from their
mistakes
* Can they even get
accurate feedback
Detection Difficulty 6
Violation of Conversation Rules
In daily-life:
* Probes in conversations can violate social norms
* Can be seen as strange, inappropriate, or impolite
* “Could you elaborate on that”
* “Can you repeat what you just said?”
* Scanning other person’s face and body for cues of deceit
also strange and inappropriate
* Doesn’t apply as much to law enforcement interviews
Detection Difficulty 7
Some people are just good liars
a) Natural behavior disarms
suspicion
* Ex. Bill Clinton
b) Don’t find it cognitively
difficult to lie
* Can easily think of convincing and
plausible lies
* Rehearsing can help
– Identify and describe the qualities of good liars (Hint: There are 6).
Good liars 1-2
Some people are just good liars
a) Natural behavior disarms
suspicion
* Ex. Bill Clinton
b) Don’t find it cognitively
difficult to lie
* Can easily think of convincing and
plausible lies
* Rehearsing can help
Good liars 3-4
c) Don’t experience emotions (ex. fear)
when lying
* So no behaviors to suppress
* Absence of emotions can be related to:
i. No remorse for that incident
ii. Practiced at feeling confident when lying
iii. Lack of emotion generally (i.e. psychopath)
d) Good actors
* Good at displaying honest demeanor
* Notice suspicion quickly and then alter their
behavior
Good liars 5-6
e) People believe attractiveness = virtue and
honesty
* Can lead to inferences of trustworthiness
that facilitate the liar’s success
* “He has an honest face”
f) Who are “good psychologists”
* Good insight into another’s thought
processes
* Know what they want to hear, how to convey
it persuasively
* Emotional intelligence
Good Liars
a) Natural behavior disarms suspicion
b) Don’t find it cognitively difficult to lie
c) Don’t experience emotions (ex. fear) when lying
d) Good actors and display seemingly a honest demeanor
e) Attractiveness may lead to inference of virtue and honesty
f) Who are “good psychologists”
EXAMINING THE WRONG CUES
- Came about because believe liars feel
bad for lying, continue because of: - Illusory correlations: perceiving a
relationship between variables when
none exists - Ex. told someone is lying, then
overestimating the amount of gaze
aversion you saw
- Confirmation bias: tendency to seek
information that confirms our
existing beliefs
* Over attending to what supports our beliefs - Belief perseverance: when we have
information that disconfirms our
false belief we disregard/downplay it
Overemphasis on Nonverbal Cues
*When observers notice nonverbal
behavior and speech content don’t
match, they typically rely on the
nonverbals
* Ex. Job applicant with reserved
demeanor claims to be enthusiastic
about job
* What does the interviewer think?
*Why do we pay so much attention to nonverbal cues?
* Used to it – do it all the time
* When expecting lies:
* Police have little interest in listening to
denials
* Prefer to look at bodily signs to confirm
deceit
* More cognitively demanding to examine
verbal ones
* Training places greater emphasis on
nonverbal cues
The Othello Error
*Misinterpretation of signs of
nervousness in truth tellers as signs
of deceit
*Just knowing that someone
suspects you of lying, like a cop,
increases arousal
* These cues can be mistaken for
deception
o Use of heuristics
* Availability heuristic
- Heuristic =
- Mental shortcut
- Common sense
- Intuitive judgments
- Use these instead of
carefully scrutinizing a
person’s responses
Availability Heuristic: - Estimating the likelihood
of events based on their
availability in memory - Most encounter more
truthful behaviors, so we
assume most behavior we
encounter is associated
with honesty - Police opposite
- Anchoring heuristic
- Making insufficient adjustments
from initial value - If preoccupied with thinking
someone is deceptive, will
make insufficient adjustments
when contrasting evidence
emerges
- Probing heuristic
- Observers’ tendency to believe a
source more after the source has
been probed - We believe probing is a good way to
detect deception - So if no clear signs of lying come out
during probing, more likely to be
believed
- Representativeness heuristic
- Judging something based on
how similar the aspects are
to the prototypes in our
mind - Judging looking away as lying
- Consistency heuristic
- Consistency heuristic
- Consistent statements = truthful
- Inconsistent statements = liar
- NOT true
- Facial appearance heuristic
- Honest face = attractive and
symmetrical faces, or baby-faced - Dishonest face = appearance
that suggests anger and
unkindness
o Existing interview techniques
- Disclose evidence early, which can facilitate ease of
lying - Allows liars to change their story
*Accusation of lying can lead suspect to stop talking - May elicit same responses in liars and truth tellers
- Afraid of not being believed
o Overconfidence in lie detection skills
- Professionals more confident but not
more accurate - Not unique to police
- Can be harmful
- Stops searching for evidence
- Reduces motivation to learn about lie
detection
› Opportunities
– What is meant by an “information-gathering interview style”? Is this the typical approach used in deception detection? If not, what is the typical approach used?
-the interviewer gathers all evidence, good or bad, before making a conclusion on a suspect (guilty or not guilty)
-a focused, structured conversation in which the goal is to seek out information from another person
accusatorial approach technique. Most of the time, interviewers believe someone is guilty before questioning that they go into the questioning process stating that the suspect/ interviewee is guilty and they carry on the questioning process with that accusation
– Why is the information-gathering approach proposed to be advantageous?
*All 2Bs need interviewees to talk
* If use accusatorial style?
*Information-gathering style good because:
* High # details
* More nonverbal and verbal cues
* Safeguard against false confessions
* Interviewers less likely to have tunnel vision
– Strategic Questioning Approach
o What does this approach entail? That is, how do these strategies attempt to detect deception?
- Uses specific questions that elicit the most differential
responses between truth tellers and liars
Ask unanticipated questions (spatial,temporal, draw layout) 86% truth tellers 79 liars
o What ways (there are 2) does this approach attempt to detect deception?
1.Ask Unanticipated Questions
* Liars prepare themselves (tend to be overly scripted)
* So, ask questions they don’t prepare for:
* Spatial
* Temporal
* Draw layout
* Across multiple interviews, see if consistent
* Accurately classifying truth and deceit from anticipated (~
50%) & unanticipated (~80%) questions
2.*Ask Temporal Questions when Suspecting a Scripted
Answer
* Don’t just ask about that event or location
* Because can just remember another time
* Instead ask about information specific to that particular
place at that particular time
o Why are these strategies thought to work to detect deceit better than traditional approaches?
The Devil’s Advocate Approach
• Detect veracity in opinions
• (not as useful in traditional police interviews)
• Ask them to argue their opinion on an issue, and then
argue against their personal view
• Truthful opinions:
• More info, longer responses
• Observers judge as more plausible and emotional
• 86% truth tellers and 79% liars correctly classified (Leal et al., 2010)
– Strategic Use of Evidence (SUE) Technique
o What does this technique entail?
- Strategic Use of Evidence (SUE) technique
- Truth tellers and liars differ in their strategies
- T forthcoming, L avoid or deny
o How does this approach attempt to detect deception?
Pre-Interview
*Investigator plans interview
* Identifies pieces of potentially incriminating information
* Formulate questions (open ended and specific) addressing them
1. Free recall phase: Suspect describes his/her activities
* Truth tellers more likely to discuss critical pieces of evidence
* They have nothing to hide
* Will recall all that they can remember
* BUT may forget to mention, or may have forgotten it
* Liars don’t want to associate themselves with the crime
* Will avoid mentioning critical elements
2. Questioning phase
* Ask about the critical details (Did you see a briefcase?)
* Interviewer doesn’t mention any evidence (i.e. fingerprints)
* Because liar could deny, and then can bring up this contradiction later
* Critical that the nature of these questions does NOT reveal what the
investigator knows
* Truth teller would likely reveal having touched that item
3. Secure the suspect’s statement
* Review the interview
* Make sure you have answers to key details
4. Reveal evidence, suspect explains any contradictions
* However not all contradictions are signs of deceit
o What is the accuracy of this technique? That is, how many truth tellers and liars are correctly classified using this technique?
- SUE 85.4% & other 56.1% accuracy rate (Hartwig et al., 2006)
- Guilty suspects contradicting evidence more
– Imposing Cognitive Load
o What does this technique entail? How does this approach attempt to detect deception?
*Makes the interview setting more difficult for all
interviewees
* Affects liars more than truth tellers
* Results in enhanced differences
*Why is lying more cognitively demanding?
o Why is lying proposed to be more cognitively demanding than telling the truth?
- Need to formulate lie
- Monitor and control their behavior to appear truthful
- Monitor interviewer’s behavior
- Preoccupied with acting/role playing
- Have to suppress truth
- Have to activate lie
o What are the different ways that cognitive load can be imposed?
How do we exploit this?
* Instruct interviewees to maintain eye contact
* Maintaining is distracting
* Reverse order (further increases cognitive load for all)
* Counter to expectations, hinders reconstructing event from
schema
* Officers’ classification accuracy: 40% usual order, 60% reverse
order
o What are potential limitations or issues associated with this approach?
*Issues?
* Makes truth tellers feel uncomfortable
* Can lower the amount of info shared
* Doesn’t protect truth tellers from appearing suspicious
o What is the accuracy of this technique? That is, how many truth tellers and liars are correctly classified using this technique?
think suspect as a cup, water is the lie they are telling and they keep pouring and pouring thus their mind overflows and they tend to make more mistakes (cognitive cues rather than behavioral)
