Presentation on theme: "J. P. Rosenfeld, Ph.D."— Presentation transcript:
J. P. Rosenfeld, Ph.D. firstname.lastname@example.org
We should spend an equal time on phenomenology and MECHANISMS of deception…. …as we do on DETECTION of deception. But there is a lot more research-based (real) knowledge about the latter, so most of the time, that’s what we will cover.
Regarding detection; there are two approaches: 1. Behavioral (a) non-verbal (b) Verbal 2. Physiological: Nervous system activity. ….We start with Behavioral:
Are the following notions True? 1. People typically reveal their lies by fidgeting, acting nervous, avoiding eye contact, etc. 2. Therefore, we are rather good lie detectors (unless we are very stupid). 3. This is especially true when we detect lies in those close to us. 4. Criminals, con-men, professional crooks, and such, however, are harder to spot for us lay people. 5. Fortunately, trained professionals (police, FBI) are superior lie detectors, so they protect us against pros.
From Bad-est to least bad: (1) Outright Lie– (total B.S.) John Edwards: “I am not the father of that child, no way, I’ll happily take a DNA test….” He was stating “I didn’t do it” while knowing he did.
(2)Exaggerations (overstatements) or Minimizations(understatements) “I am the most eminently famous researcher in the Psych. Department.” (but almost…) “This is an important discovery of mine not yet published” (which was actually rejected by one journal and now in review at another.)
(3) Subtle Lies (Omit details) Clinton: “Ah did not have sex with that woman, Miss Lewinski…” (Not according to the usual definition: intercourse.)
(4) Concealment… “How was your day?…mine was as usual…” [Heaven forbid she asks me about my day!]
(1) Gender: Men tell more self-oriented lies. Women tell more other oriented lies
(2) Age What is definite minimum age for lies in children? (2,4,6,8,10) See Vrij, P. 27. What motivates youngest children’s lies? (Gain of say cookies? Avoid punishment? (earliest lies). Make a good impression?)
(3) Personality Type In romantic relations: (a) attachment style: avoidant (lack of trust, keep people at distance)…..these folks lie to keep others at a distance. Versus anxious attachments: lack of self- esteem. These people lie to look good as they feel bad.
(b) Psychopathy The types have no empathy or sympathy for others. They regard others as pieces of themselves, and objects of manipulation—like their own limbs. These are big time liars to everyone they might wish to manipulate. Superficially charming, they get away with it for a while…
(c) Extraverts and introverts Outward/sociable vs. reserved. Which are the bigger liars?
(d) Self-consciousness: These are very concerned with impression they make, so how do they behave with respect to deception? In this connection, one speaks also of social anxiety: they lack self confidence, so they tell tales.
DiPaolo’s group emphasizes 3 theoretical perspectives: During deception, 3 phenomena occur that may yield “tells”: 1) emotional reactions: guilt, fear-- --and delight. (delight?) Guilt low eye contact Fear stuttering, blinks, squeals. Delight (of duper) excitement, inappropriate laughter. (Ekman)
What else does liar experience? 2) mental (task) demand, also called cognitive load. Liars will also tend to look away, so as to concentrate on made up details. Except when they monitor you to see if you believe. 3) Attempted self control of behavior to avoid tells. Not easy. Voices break, facial expressions occur: Ekman’s micro-expressions.
These are theories of what should happen. Moreover…
…these effects are affected by certain other factors, e.g., GUILT—The degree of guilt felt depends on personality. Consider Psychopathy. & Consider Stakes. & Consider sense of righteousness or duty felt by CIA agent. FEAR– Experienced liars of whatever breed have less fear. EXCITEMENT– helped by type of audience. Also, if it’s a big conquest, or else, no.
More… COGNITIVE LOAD--- also depends on verbal skill-intelligence and experience. (Vrij is wrong about Psychopaths feeling less load.) Degree of rehearsal also makes a difference (practice makes perfect!). No transparency illusion. So more monitoring of other. SELF CONTROL depends on Psychopathy.
Vrij is a pain, but best we have..(E.g.Box 3.1 p. 47)…. …and his best statement is on the top of p. 49. “ …the relationship between lying and non-verbal behavior is complex.” The implications of this statement regarding development of non- verbal “tells” is what?! (Life is not Poker.)
Field Studies.(Define.) We want to compare liars vs. truth-tellers, but… Difficulties: 1)Getting videos: (Are cameras always running?) 2) Establishing “Ground Truth.” 3) Controls: only possible in lab to have unconfounded conditions—so not many field studies re: nonverbal cues are out there…
What’s a Confound ? Consider our deception feedback study:
OK, how about lab studies? Pluses: Ground truth easy to get by design. Likewise, un- confounded control conditions. Minuses: Lies are instructed. So what happens to guilt? fear? What happens regarding stakes? You can offer lots of money, but not punishment (as in real life). DECEPTION HARD TO STUDY!
Bottom Line: Vrij’s Appendix 3.1(p. 90) makes very clear that there is NO reliable non-verbal sign of deception. There may be trends and even significant group effects (explain), which support theoretical views noted above….. **But in D of D, the key statistic is INDIVIDUAL HIT RATE (as utilized in d’ or AUC from SDT).
Dramatically: Is there such a thing as “lyin’ eyes?” Are gaze or eye contact helpful? (p. 60) Vrij says no, but there is new research: N. Cohen, Frank. *Are liars more emotional than truth tellers? Why or why not? (p. 61) [HINT: Is it only liars who feel emotion?]
Table 3.1 (p. 57) in Vrij is about effect size. J. Cohen's d = M 1 - M 2 / s pooled where s pooled = � [(s 1 � + s 2 � ) / 2] In Table 3.1, only 3/18 d values are >.30 (moderate) in the big meta analysis of 100 behaviors. Remember, d is a GROUP measure!
Vrij’s “Group Differences” (p.67)…. Very suspect! As is rest of chapter about Clinton, Saddam Hussein, Huntley. Amazing that he says (p.89) look for the cluster of c(l)ues to deception, not single c(l)ues. Which cluster? “There is no straightforward answer….”
Vrij description of possible verbal signs (“cues”)… ….as in his box 4.1 list (p. 101) is mostly pathetic, i.e., wrong (imho). On the other hand, sometimes one has to say, “duhhh!” as when he states that direct statements are more credible than evasive ones. Obviously plausibility helps! As does consistency (lack of contradiction).
But Vrij best statement is… “As I will demonstrate, a verbal cue uniquely related to deception, akin to Pinocchio's growing nose, does not exist.” (p. 103) Again, an appendix (4.1 yuk!) shows some trends & group effects as supporting some views in Box 4.1. Again, clusters> singles. But which cluster? No one knows.
Vrij indulges himself with many “I think..” type ideas. That’s fine. Be sure you do not confuse these hypotheses for facts! Note: people & researchers always start out with what appears obvious, like twitches & speech signs. These all are ultimately controllable, unlike physiology (looking ahead).
Henceforth…. We will be looking at more specialized and developed approaches to detecting deception. Vrij still likes “more immediate” (non-physiological) tools, because they are allegedly quick, easy, & cheap. Imho, he stretches things by emphasizing how laborious some methods are...
OK, fMRI requires a $1M+ machine and an annual budget of >$1M… But when Vrij states (p. 189) that EEG/ERP recording usually requires 10 or more scalp electrodes, he exaggerates: 2 (actually 1) will do, and it takes only 5 minutes to hook up. But Vrij & we will go on with SVA, RM & possibly SCAN, imho, unphysiological extensions of what we just did…
For SVA, go to power point on 323 web site called….. “Statement Validity Analysis” and read Vrij chapter 8. I will not lecture on it. But I will lecture on the Implicit Association Test. Go to this web site and take a demo test: https://implicit.harvard.edu/im plicit/demo/
Reality Monitoring… RM started not as a DoD method, but rather as a discipline in Cognitive Psychology to study on a theoretical basis, the differences between perceived versus imagined experience; as with false (but honestly believed) memories.
What are the characteristics of Real versus False Memories….. …with regard to: Sensory Information? Contextual Information? Affective information? Think of dimensions of clarity versus vagueness? Give examples of what you might actually remember about an event.
This Q & A system of M. Johnson sorta works, but… What happens as time passes? So what do you remember better, last week or when you were 3?
Actually… Actually, it turns out that Physiology (ERPs) come to the rescue again regarding false memories… which is good because RM tool isn’t so great..(p. 265) …as we will see later.
If RM is not a perfect false memory detector, then why.. …would we think this strategy would be a good deception detector? Are there differences between false memories and deceptions? HINT: What do subjects believe about veracity of f.m. and lies?
RM Criteria (Sporer ‘97) some overlap with CBCA: based on interviews:non- standardized From Vrij Table 9.1. The first 7 should be there in true statements. 1. Clarity—clear sharp, vivid statements 2. Perceptual info.—details of smell, sound, etc. 3. Spatial info.—details of location, seating arrangement, object location. 4. Temporal Info– When things happened, and in what order. (continued…)
Four more… 5. Affect detail—How subject felt:” I was disgusted when I saw the body…” 6. Reconstructability of the testimony in detail. 7. Realism: Is the story plausible, realistic, logical? 8. Cognitive operations. Should be less in true story: It shouldn’t be necessary to make inferences: “He appeared nervous.”
The RM method usually involves 2+ raters scoring tape. Inter-rater reliability should be and is found by research to be high. Good as CBCA, anyway. Vrij thinks it’s easier to learn and teach, because… There are fewer criteria which are more concrete and thus less subject to interpretation.
Vrij’s review of RM research in Appendix 9.1 has limitations: Not all reviewed studies are peer- reviewed publications. Not all studies are given! Scoring not standardized. Some listings lack inter-rater data. Only recent events are studied. RM is problematic in children. Etc, etc. maybe not important ….
...because: Appendix 9.1 shows a mostly mixed pattern. Average accuracy is 68.8 % overall, which mean many false alarms (about 29% in truth tellers) and misses (about 34% in liars). I.e., group but not individual results.Yes, RM beats flipping a coin, but not by much. More work is needed. (Physiology wins.)
Israeli tool: Vrij: Widely used, though Not much researched, nor endorsed by researchers.
Basic assumption: A memory based on actual experience will differ in content and “quality” (?) from an invented or fantasized memory. (Duhhhh!) Also problematic: Not all lies are invented out of whole cloth. Some are substituted actual memory, as in most alibis.
Proceedure: Suspect writes in handwriting a statement of events in absence of investigator (to avoid contamination). Statement is then scored on several criteria:
The Criteria (+ = seen in truth tellers. V means vs. CBCA) 1. Direct denials + 2. Specific identifications + 3. Cross-outs(against instructs.) – V 4. Vague memories – V 5. 20-50-30 structure + 6. Emotions + 7. Subj/obj time correspondence +
More…. 8. Events in chronological order + 9. Missing info: :”A bit later..” - 10. 1 st person, present tense + 11. Pronouns “I” Ownership. + 12. Change in language(???): Change from “conversation” to “Discussion.” - if not justified. Too subjective (imho)
Research results with SCAN: 1. Field study:.77 TTs,.88 Liars at best with Denial criterion. ….But, as with almost all field studies, no ground truth!!!!! So, fuggedaboudid! 2. Lab Study(So no ground truth issue): Three crirteria utterly failed to discriminate liars and truth tellers!! So, fuggedaboudid!
Final field study… Again no ground truth!! Though they claim75% TT accuracy, 80% liar accuracy. Great lack of consistency among SCAN users: So, fuggedaboudid! Bottom SCAN line: Little empirical support, little standardization. Thus the widespread use is stupid.
Polygraph: Does not mean “lie detector.” Means a machine with many (poly) channels of visually presented (graphical) information; in inked paper or laptop display format. A Polygraph machine can be and is used in many fields of Psychophysiology
2 Major Protocols currently used : Comparison (“Control”) Question Test (CQT)-- beloved by enforcers, ‘cuz it’s easy to use (“Didja do it?”) and tends to elicit confessions—but hated by academics who prefer the Guilty Knowledge Test (GKT better known as the Concealed Information Test (CIT), since knowledge can’t be guilty (just perps.) Both utilize autonomic arousal.
Why do us professors frown on CQT? Pre-test interview cannot be standardized. It compares arousal responses to relevants. & “controls.”There can never be true comparison control questions in the scientific sense of control.(Yet there could be better versions.) High false positive rate (which CIA et al. don’t care about….)
Why do we love CIT? It compares arousal (?) responses to critical (probe) and non-critical (irrelevant) stimuli. There are usually 6 or more multiple choice questions with 1 + 5 choices per question. (Throw away 1 st.) Thus for each item, the P(chance hit) = 1/5=.2 For 6 INDEPENDENT items, probability of subject hitting on all 6 by chance =P =.2^6 =.2 x.2 x.2 x.2 x.2 x.2. Use Bernoulli for chance hits on < 6. Thus you can reduce the false positive P as low as you like by adding independent items (not always so easy).
Since averages are so much cleaner than single sweeps, …and show the true stimulus-evoked event that is time-locked to the eliciting event, and are more noise free, ….it obviously makes sense to compare averages rather than single sweeps, that is, to do analysis, like t-tests on averages. People did that in comparing group ERPs or grand averages.
For example, The schizophrenic group average versus the normal average or the well-trained group average P300 vs. that of the untrained group. Remember, in a group, each subject has an average ERP. ….but within a single subject, there are only single sweeps to compare
In Bootsrapping… …..the original set of single sweeps is repeatedly randomly sampled –but with replacement— …yielding multiple averages in a single subject. Let’s say there are 6 repetitions of sampling of 18 single sweeps:
….that look like real average of original set but with variations
PersonHeight Self Esteem 1684.1 2714.6 3623.8 4754.4 5583.2 6603.1 7673.8 8684.1 9714.3 10693.7 11683.5 12673.2 13633.7 14623.3 15603.4 16634.0 17654.1 18673.8 19633.4 20613.6 Correlation Example Let's assume that we want to look at the relationship between two variables
Finally, we'll look at the simple bivariate (i.e., two-variable) plot:
Now we're ready to compute the correlation value. The formula for the correlation is: