A critical review of Telling and Detecting Lies

Participants

The ability to detect lying was evaluated in 509 people categorised in 7 different groups.  They all had a professional interest in lying, such as members of the US Secret Service to students.  The videotape showed 10 subjects who were either lying or telling the truth when describing their feelings.  Only the Secret Service performed better than chance, and they were notably more accurate than all of the other groups.  The research states two experimental hypotheses: Hypothesis 1 predicted that accurate observers would report using nonverbal clues more than would the inaccurate observers.  Hypothesis 2 predicted a positive correlation between accuracy in detecting deceit and accuracy in recognizing micro-expressions of emotion.  

Has the design of the study been clearly specified?

This research pioneered the use of behavioural samples, drawn from a set of videotaped interviews that prior behavioural measurement, have shown when subjects lied or told the truth.  This was quantified through FACS the Facial Action Coding System; (FACS) is probably the most known study of facial activity.  FACS provides a linguistic description of all possible, visually detectable, facial changes in terms of so-called Action Units. (Ekman et al 1978)  Vocal measurement made a clear distinction between the lying and truthful interviews.  It was noted that there was an increase in pitch when subjects lied.  When both cues were used together it was possible to classify 86% of the subjects correctly either as liars or truthful. (Ekman, et al 1991) Because of the known behavioural differences between the honest and deceptive samples, the research could focus on the question, How well could the participants detect deception?

How appropriate are the design and any measures used?

The design was appropriate because it supported the emphasis of the use of non-verbal cues as they represent 55% of our communication.  The ten subjects shown on video had already participated in a deceit exercise so they were all well motivated to hide their deception.  There was a question to be asked as to what was the relevance of not including the college students and special interest group from completing the hand written responses.  There was also an ethical question to pose, Was it morally right to promote deception?  

Findings

Outline the key findings?

The key findings are the participants in all of the groups, except for special interest and students, gave open-ended descriptions of behavioural cues they used in judging whether someone was lying on three occasions: prior to seeing the videotape.  After judging the second person shown on the videotape and after judging the eighth person shown on the videotape, the handwritten answers varied in the amount of detail given and in the number of verbal and behavioural cues mentioned.  Hypothesis 1: all responses that referred only to speech cues (e.g., “speech latency”, "evasive," "talks too much," "contradicts herself"), responses that referred only to non-verbal behaviors (e.g., "voice strained," "gaze aversion," "false smile," "self-manipulations"), or responses that mentioned both speech and nonverbal behaviours. (Ekman et al 1978)  Across both items and all participant groups, 37% of participants reported using speech clues alone, 29% reported nonverbal clues alone, and 25% reported using both verbal and nonverbal clues.  This is consistent with Knapp’s (1989) study on the cues Military interrogators utilise in order to gain information.

How well do the authors justify their findings?

The results directly contradict those reported by Kraut and Poe (1980), DePaulo

and Pfeifer (1986), and Kohnken (1987), all of whom found that occupational

groups with a special interest in deception did no better than chance, or no

better than college students did in detecting deceit.  

• First, they did not examine the Secret Service, unlike Ekman.  If Ekman had not examined this group, then the results would have replicated previous researchers.  

• Secondly, Ekman revealed that there were both highly accurate and inaccurate participants by using subject-by-subject analysis.  

• Thirdly, Ekman used a benchmark of samples positively determining honest and deceptive behaviour that he knew through prior behavioral measurement that did differ.  

Previous investigators did not establish that their samples of honest and deceptive behavior actually differed, or if they did, that they permitted accurate classification of most of the subjects, and so their participants might not have had much of a chance to detect deception.

Are the interpretations of the findings appropriately derived?

Critics may raise some disparity arguing that there were differences in the behaviours of honesty and deception, but these could be measuring the ability to detect differing poles of emotions rather than deception.  This argument would indicate that their were two sources responsible for the negative effect the fact that they were watching a gruesome film would arouse negative emotion and the fact that they must hide their deceptive behaviour with the overriding fear of getting caught which would unveil internal negative emotions.  A question must be raised as to whether people who are accurate in detecting one type of lie are also accurate when judging a different type of lie:

Methodology

What do you consider are the main strengths and weaknesses of the study?

• Deception was based on concealment of strong negative emotions only

• Simple test not requiring many subjects total of (31)

• Participants would be put under the pressure of time with the 30 second window in order to make a decision.

• Both variables were equidistantly distributed between the 10 young college girls.  The participant’s accuracy score ranged from 0-10 correct.  The participant would obtain only a chance total accuracy score if the participant were to judge every subject to be lying or truth telling.  

• A good idea to have independent verifier’s interpreter agreements to analyze subjective material from the handwritten responses.

• • When detecting micro expressions it is not at all certain that each facial expression is able to be displayed on the face can be classified under the six basic emotion categories (happiness, sadness, fear, anger, surprise, and disgust)

• • Ekman’s description is of the six prototypic basic emotions, which are linguistic, thus, ambiguous)

• Although the lie-detection measure contained different behaviours in honest and deceptive samples, some critics might argue that the study measured the ability to distinguish positive from negative emotion rather than the ability to detect deception.

• Although the Secret Service produced better results it was only a small sample assessed.

• The study appears to lack any ecological validity as there is discrepancy as to whether the same results would be recorded if the experiment was repeated.

• Measurements of the behaviors shown in the videotapes suggest that they do not differ in affect valence

        

Conclusion

Some lie catchers ie, the secret service can actually detect deception using non-verbal cues aswell as verbal.  In their occupational environment some groups may be better exposed than others when detecting deception.  Judges cannot always see the faces of the defendants and rely more on listening to the words than observing behaviour.  The polygraph tester’s, were more focused on the readings from their machines and how they frame their questions.  Psychiatrists eventually believe that the truth will eventually uncover itself so they didn’t pay much attention to lies.  Police departments believe that everybody lies to them, so they have no discernible template to relate to when they have to make a correlation between the truth and deception so they shift focus to gather evidence in order to secure a conviction.  The Secret Service group who performed much better than any other group, believe that they are dealing with a much lower base rate of liars and most perpetrators are carrying out their action through braggadocio  and not serious so they are much more focused on signs of deceit.  More research is needed to better understand the medium of lies their construction and recall.

References

DePaulo, B. M. & Pfeifer, R. L. (1986). On-the-job experience and skill at

detecting deception. Journal of Applied Social Psychology. 16, 249-267.

Ekman, P., & Friesen, W V. (1978). Facial Action Coding System: A technique for

the measurement of facial movement. Palo Alto, CA: Consulting Psychologists

Press.

Ekman, P., O'Sullivan, M., Friesen, W. V., & Scherer, K. R. (1991). Face, voice

and body in detecting deceit. Manuscript submitted for publication.

Knapp, B. G. (1989). Characteristics of successful military intelligence

interrogators (USAICS Tech. Rep. No. 89-01). Fort Huachuca, AR: US. Army.

Kohnken, G. (1987). Training police officers to detect deceptive eyewitness

statements: Does it work? Social Behaviour, 2. 1-17.

Kraut, R. E., & Poe, D. (1980). On the line: The deception judgments of customs

inspectors and laymen. Journal of Personality and Social Psychology. 39, 784-

798.

Kraut, R. E., & Poe, D. (1980). On the line: The deception judgments of customs

inspectors and laymen. Journal of Personality and Social Psychology. 39, 784-

798.

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