deception Flashcards
Methods of Detecting Deception
observing/talking to ppl ( can be done anywhere)
phsyiological techniques (polygraph, brain measure)
if ur nervous does that mean u r lying or vice versa
neither
Behavior Cues
to Lying
North Americans tell 1-2
lies per day
Even Koko the gorilla has
told a lie or two
We assume that telling a lie
creates a physiological
change
Are non-verbal cues of
deception harder to hide?
hand guesters
truth = rythmic
lie=speech prompting
DePaulo, Lassiter, & Stone (1982) findings (research w ppl lying and either asked to focus on vocal tone or not)
the half asked to focus on vocal tone were better at detecting the lies
the pitch and how it chnages
Verbal Cues to Lying (3)
higher pitch, speech
disturbances (ummm, ahhh, uhhhh)
Slower rate of speech (more intentional, talking slow bc unsure of what to say)
Adams &
Harpster (2008) - innocent vs guilty how to tell
Innocent
◦ Requests help, corrects
misinterpretations, rude
+ demanding (they care more about getting things right, spoke quick, cooperative, emotion, sense of urgency)
Guilty
◦ Irrelevant details, state
victim is dead, polite +
patient, less emotion, more blame
Verbal Cues to
Lying
Liars provide fewer details than truth-tellers
Liars’ stories are less compelling than truth-tellers
* Less plausible
* Lacking logical structure
* More discrepancies
* Less engaging
* Less fluent
* More nervous, tense
Truth-tellers more likely to spontaneously correct
their stories, more likely to admit lack of memory
Paul Ekman’s Microexpressions
brief facial expressions that reflect the emotion a person
is feeling
why r microexpressions impotant
Deception can be difficult to detect if the liar is not showing an obvious
emotion
are there actually wizards like ekman said
no
Can we reliably detect deception?
Laypeople detect deception at a rate of 54% accuracy
Trained professionals detect at a rate of 55% accuracy
just 50/50 so chance
Why are we so bad at detecting lies
◦ People rely on stereotypic beliefs about lying → gaze aversion + fidgeting
◦ Truth-bias: people judge more messages as truthful than deceptive
◦ The differences between truth-tellers and liars are small
we get little feedback on if we r right
does cofident mean accucraten
no
men or women better at detecing lies in close relations
women
when highly motivated….
worse at lying
why are Officers are better at catching high-stakes lies
They are more familiar with settings that involve
high-stakes lies
◦ Lies are easier to detect when the liar is motivate
the othello error
too readily interpreting signs
of nervousness as deception
Polygraph
device used to record
an individual’s autonomic nervous
system response
problem w polygraph
Physiological states associated with
lying are similar to those associated
with
◦ Anger
◦ Anxiety
◦ Embarrassment
◦ Fear
The Comparison Question Test
neutral then relvant then comparion
neurtal = whats ur name
relveant = relveant to the case
comparsion =emotional arousinf
CQT guilty
Relevant > Comp
CQT inoocent
comp>relevant
The Concealed Information Test
Does not detect deception
◦ Does the person know details of the
crime?
Multiple choice Questions
◦ One critical option, multiple foils
Guilty → larger physiological response
to the correct option than the incorrect
options
Skin conductance is most common
physiological response
Polygraphs: Accurate or Not?
Lab Studies → participants try to lie about a
mock crime
- bad external validity
◦ Stakes are low
Field Studies → compare accuracy of
‘original’ examiners to ‘blind’ evaluators
◦ Blind evaluators only read charts, not swayed
by other cues
◦ Difficulty establishing ground truth
CQT Accuracy
Confessions used to classify suspects as
innocent or guilty
◦ Among guilty → 84-92% accurate
◦ Among innocent → 55-78% accurate
◦ 9-24% suspects falsely identified as guilty
Countermeasures
Techniques used to
conceal deception
Physical → biting
tongue, pressing toes on
the floor
Mental → counting
backward by 7 from 200
Other Physiological Techniques
EEG, facial thermal imaging, fMRI
is the polygraph admissible in court
no
problems w CQT
physioloigcal changes or the lack thereof are not indicative of anything
witness the crime will impact so will if u know the suspect
novel q could throw u off if ur guilty
guilty might be habitutated to the crime and hv to response
concealed info test problem
again asuming a rxn to info is physiological
crimials might not rember every deatil of the crime
if its a big crime everyone will know about it
lots of arousal during the crime = bad memeoru about it
why should the concealed info tets be good for innocent ppl
bc so unliekly that they respond to the right answer eveyrthing if they dont know anything
when is lying easy
low stakes, low motivation
can u hv bias in polygraph
yes
expert vs laypeople polygraph
expert think bad, laypeople think good
problem: laypeople = jury
problem w polygraph neutral q
neural q doesnt elicit emotion/arousal as others so u dont hv proper basline of arousal q that u r innocent
30 mins of instruction on coutermeasures means
50% ppl incluidng guilty would pass
are other physiological techniques admissible in court
no
facial thermal imagining
maybe warm = lie
fMRI not yet bc
need to find where exactly the lying is in the brain
