Lie Detection Flashcards
How successful is the lie detection rate of experts?
Who are the most successful experts?
54%
Secret service agents, professional gamblers
Why are experts not great at lie detection?
They rely too much on liar stereotypes (no eye contact, fidgeting, body language, voice)
What would be better methods for lie detection experts?
Content analysis - focuses on word choices, inconsistencies, factual errors
Increase cognitive load - reverse order of events, review details, make it more mentally taxing to keep story straight
What are the common themes among lie detectors?
Lying causes fear and therefore:
Fear activates the sympathetic nervous system
E.g., the dry mouth test
E.g., the bread and cheese test
What was the 1st “Lie Detector”?
It was a measure of blood pressure
By William Marston (1915)
John Larson
He was the first “police psychologist”
Blood pressure + heart rate + respiration = polygraph
His polygraph was used in high profile murder cases at the time
Polygraph means…
“many writings”
Explain the “Keeler Polygraph” by Leonarde Keeler
Blood pressure + heart rate + respiration + electrical resistance (sweat) = polygraph
Portable
Patented
Promoted Professionalized
Polygraph interpretation nowdays
Computer assignment
Automated process
Look to see if the indicators are low or high
Polygraph: Relevant-Irrelevant Technique (RIT)
Relative arousal for:
o _________ (unemotional questions)
o ________(crime relate) questions
Irrelevant
Relevant
Polygraph: Reid Control Question Test (CQT)
o True “control” questions must be _______, but not related to ______ ______.
o Subjects asked for ______ _____ (an instructed lie) and _____ _______ _______.
o It is now _______ _______.
o True “control” questions must be emotional, but not related to current issue
o Subjects asked for directed lies (an instructed lie) and guilt complex questions
o It is now standard method
Explain the Guilty Knowledge Test (GKT) (4)
Who is it by?
Based on the recognition of details
Multiple choice format
Required generally unknown details
By David Lykken
Polygraph and accuracy issues
o _________ ______ ____ ___ ______ (no “Pinocchio response”)
o _________are not ___________
o ______ ______ affects results (psychopathy, anxiety, etc.)
o ___________ __________ influence results (medications, stress)
o _____________ (mental + physical)
Autonomic changes are not specific (no “Pinocchio response”)
Procedures are not standardized
Mental status affects results (psychopathy, anxiety)
Examination conditions influence results (medications, stress)
Countermeasures (mental + physical)
What errors in detecting deception? (3)
Missing a guilty person
Accusing the innocent (false positives)
Errors = more likely to be false positives
Polygraph says for TRUTHFUL - __% actually lying, __% actually truthful
25%
75%
Polygraph says for LYING - __% actually lying, __% actually truthful
55%
45%
Detecting Deception - Legal Issues
Daubert failure: “___ ____ __ ____ ____ _________”
Federal, military and most state courts _______ ________
Employee P________ P_________ A___ (1988): FBI, CIA, NSA, DEA, Secret Service, police and public safety job are ___________
Still used for ___ offenders and ________ ________ _____
Daubert failure: “the jury is the lie detector”
Federal, military and most state courts exclude polygraph
Employee Polygraph Protection Act (1988): FBI, CIA, NSA, DEA, Secret Service, police, and public safety jobs are exceptions
Still used for sex offenders, and national security cases
_____________ and _______ are used to elicit confession
Intimidation; leverage
Pentagon report: __% of info from ________ interviews comes from the threat of a _________
90%; security; polygraph
Why are polygraphs used if they are not that accurate? (3)
It is a useful interrogation tactic
The threat of the polygraph is useful
Intimidation and leverage
Other Methods
EEG is known as “_____ _____________”
(people are trying to push it to be used in court)
brain fingerprinting
P300 = r___________
Shows…
recognition
shows images on screen and see brain activity with objects which seem familiar vs. not familiar
How does Functional MRI (fMRI) detect deception?
Blood flow in brain regions associated with lying
A group level of analysis
