Lie Detection Flashcards
Background to Lying
avg person tells 2 lies a day
police officers, customs officers, doctors, and fbi agents are no better than undergrads at detecting lying
unrelated to accuracy of deception: eye contact, hesitations, number of words spoken
cues related to accuracy of deception: more tense, pupil dilation, fewer details, fewer blinks, higher voice pitch
how to detect: ask for elaboration, repeat what they said earlier
ability to detect deception
in children: still hard, but a little easier to be accurate when kids are younger
Polygraph testing
control question technique: 10 qs, some deal with past emotional behavior, some are relevant to the crime, the assumption is that an innocent person responds equally to both
issues: many examiners are former police who weren’t trained in measurement procedures
success rates: one study claims 75%, other claim 85% of guilty are lying but 50-75% of innocent are telling the truth -> false positives!
faking the test: suppress response to relevant q: mental calming, augment response to control q: bit tongue, press toes on tac
Polygraph in Courts: inadmissible in 5 states
Functional Imaging
Feigning memory: prefrontal-parietal-subcortical circuit (frontal lobe activation), memory task accuracy 69-100%
Use in courts: companies setting up to market lie detection, 3 attempts to have fMRI data admitted
Neurobio of Lying
kinds of liars: pathological, conning, deceitfulness, lies for sickness benefits
more prefrontal white matter in liars than in normal and antisocial controls
in Parkinson’s, you have a reduced ability to lie due to reduced prefrontal functioning
Lying in the psychopathic brain
deception associated w ventromedial activation and prefrontal activation
high psychopathy = low right OFC activation (r = -.72) and ventromedial PFC (r = -.56)
