Criminal prosecutors and laypersons were asked to self-assess their abilities to tell and detect lies tell truths and believe others. Prosecutors highly assessed their abilities to detect lies in others and rated them significantly higher than laypersons. They assessed their lie-detection ability significantly higher than their believing ability. Prosecutor’s beliefs about various aspects of defendants’ deception in the court of law were also discussed.

•    Criminal
•    Prosecutors
•    Deception
•    Defendant

Elaad E (2015) Criminal Prosecutors: Highly Assessed Lie-Detection Abilities and Beliefs about Defendants’ Deception. Ann Forensic Res Anal 2(2): 1017.

Accuracy in deception detection experiments has been found to be only slightly above chance level and almost never exceeded 60% where chance expectancy is 50% [1].Furthermore, even professionals who are regularly engaged in detecting deceptions, such as federal law enforcement officers were unable to distinguish between truthful and deceptive messages [2]. Vrij and Semin [3] attributed this to a lack of on the job feedback available to professional lie-detectors about whether their judgments were accurate or inaccurate.

In this context it is at odds that people tend to overestimate their lie-detection ability [4-7]. The lie-detection bias was explained by the prevailing norms that lead people not allow themselves to be easily deceived by others. Therefore, people would like to believe they possess the ability to detect lies.

People tend to overestimate their own ability to tell the truth convincingly [6-8]. The bias was explained by the “illusion of transparency” [9] which suggests that in communications, senders are anchored to their own internal experience. Although they realize that recipients are not exposed to the same information as they are their adjustment is insufficient [10] and they tend to believe that the receiver has the ability to discern their internal states and find out that they are telling the truth. Furthermore, people wish to sustain a positive self-image [11]. In this context, the ability to convince when telling the truth is a desired disposition.

The perceived ability to believe others is usually assessed slightly but not significantly above average [6-8]. Finally, people are inclined to underestimate their lie-telling ability [4-8,12]. The underestimated lie-telling ability was also explained by the illusion of transparency [9] and by the wish to sustain a positive self-image. Thus, if I am not an able lie-teller I am an honest person. In the present study, criminal prosecutors and people from the community were asked to self-assess their abilities to tell and detect lies, tell truths and believe others compared to other people. Based on previous research on police interrogators [5- 6], it was hypothesized that criminal prosecutors will perceive themselves as being better lie-detectors than lay-people. In addition, an attempt was made to investigate beliefs of prosecutors about defendants’ deception.

Earlier accounts reported that lie experts had the same incorrect beliefs about deceptive behavior as inexperienced laypersons [3,6,13]. That police interrogators believe that they do not interrogate innocent suspects [14]. That special training in deception detection leads police investigators to make prejudgments of deception [14]. That police investigators put more pressure on the suspect to facilitate confessions when they assume deception [15]. These earlier reports were tested again with a group of prosecutors.

Participants

Participants were 32 Israeli criminal prosecutors (14 males, 18 females) with a mean age of 35.6 (SD=7.3) (range = 28-60) years. Their average experience as attorneys was 8.9 (SD= 8.6) (range = 2-34) years. Their average experience as prosecutors was 7.2 (SD=6.1) (range= 2-21) years. A control group of 32 persons from the community (14 males, 18 females) was also recruited. Their mean age was 33.78 (SD=12.4) (range 23 –59). All participants were volunteers who gave their written consent to participate in the study after receiving assurance of confidentiality and anonymity.

Materials and procedure Participants were first asked to self-assess their own liedetection, lie-telling, truth-telling and believing abilities in comparison with others. For example, participants were asked: “Compared to other people, how would you assess your own ability to detect lies in others?”Answers ranged from 0 (much worse than other people) to 100 (much better than other people) with 50 (as good as others) serving as the middle point. They completed the questionnaire individually with no time constrain. Prosecutors were further presented with 26 statements about different aspects of practice in the court of law. For example, they were asked to indicate their agreement with the statement: “While cross-examining I am highly self-confident”. Responses were made on a 7 point scale ranging from (1) disagree very much to (7) completely agree.

Table 1 presents the mean self-assessed abilities computed for prosecutors and lay people. A t-test for independent samples revealed that prosecutors assessed their lie detection ability significantly higher than laypeople, t (62) = 2.24, p =.028. The other three abilities were not significantly different. Using a paired sample t-tests, it was further found that unlike laypeople, prosecutors assessed their lie-detection ability significantly higher than their believing ability, t (31) = 3.08, p=004 (Table 1).

The highly assessed lie detection ability was further endorsed by the statement: “I am convinced that I can ascertain when a defendant is lying or is telling the truth”. Twenty five prosecutors agreed (ratings 5-7) while only one disagreed (ratings 1-3). Assuming that an unbiased response should be evenly distributed above and below the middle point of the scale (4), this distribution is extremely skewed. The tendency of prosecutors to rate high their lie-detection ability was also supported by the agreement (26 vs. 1) to the statement: “While cross-examining I am highly self-confident”. The lower assessed believing ability received support by prosecutors contesting (27 vs. 1) the statement: “Usually I tend to believe the defendant I interrogate”, and by disagreeing (23 vs. 3) that: “If I interrogate a defendant for a while and did not reach the conclusion that he is lying, he must be truthful”. This attitude contrasts the common “truth bias” or the tendency to judge messages as truthful rather than deceptive when in doubt [16].

People predominantly believe that liars act more nervously than truth tellers [12] and police officers are of no exception. However, prosecutors disagreed (21 vs. 6) that: “The nervous defendant is likely to be deceptive”. Another incorrect belief about deception cues is the notion that liars avoid eye contact [3]. Prosecutors disagreed (21 vs. 4) that: “During the interrogation, a defendant that does not look into my eyes is lying”.

There is evidence that interrogators who are convinced of the suspects’ guilt conduct pressure-filled interrogations to elicit a confession [15,17]. Applying this insight to criminal prosecutors revealed that they tended to agree (16 vs. 8) that: “When I am convinced that the defendant is deceptive I will make the extra effort to force him to confess.” and disagree (25 vs 2) with the statement: “I am afraid that if I will put pressure on the defendant he will confess to crimes he did not commit”.

Kassin [14] noted that police interrogators believe that they do not interrogate innocent suspects. The present prosecutors disagree. They disputed (29 vs. 1) the statement: “There is no such thing as innocent defendants”. However, they also disputed (30 vs 1) the statement: “There are many false convictions”.

Finally, Kassin [14] indicated that: “special training in deception detection may lead investigators to make prejudgments of guilt with confidence (p. 217). Prosecutors rejected the presumption of guilt and contested (26 vs. 4) the statement: “I tend to ascertain that the defendant is deceptive before I start to interrogate him”.

The current study was designed to provide an initial glance on the perceived abilities of criminal prosecutors to tell and detect lies, tell the truth convincingly and believe others. Results replicated previous findings as to the tendency of law enforcement personnel to overestimate their lie-detection ability which was explained by the self-assessing bias or the desire to avoid an appearance of being easily deceived and therefore unprofessional. This tendency may be supported by the absence of valid corrective feedback about the accuracy of their judgments because the legal truth is not necessarily the actual truth.

Truthful defense witnesses (including the innocent defendant) might experience difficulties in conveying their truths when cross-examined by criminal prosecutors dedicated to convictions, with self-confidence about their lie-detecting skills, who perceive their ability to believe others lower than their ability to detect lies. This is particularly true for insecure but truthful witnesses interrogated by prosecutors who are not afraid to pressurize the defendant to facilitate confessions. It may be suggested that the court should acknowledge the prosecutors’ conceptions, and adopt more caution towards testimonies of insecure witnesses.

The immediate critical argument that comes to mind is that prosecutors intentionally over-rated their lie-detecting ability for purposes of self-presentation as professionals, while in practice they did not know precisely where they stand compared to other people in their ability to detect deception. Williams and Gilovich [18] indicated otherwise. They showed that people truly believe in their high self-assessments and take their estimates seriously enough to guide their behavior.

1. Bond CF Jr, DePaulo BM. Accuracy of deception judgments. Pers Soc Psychol Rev. 2006; 10: 214-234.

2. De Paulo BM, Pfeifer RL. On-the-job experience and skill at detecting deception. Journal of Applied Social Psychology.1986; 16: 249-267.

3. Vrij A, Semin GR. Lie experts’ beliefs about nonverbal indicators of deception. Journal of Nonverbal Behavior.1996; 20: 65-80.

4. Ekman P, O’Sullivan M. Who can catch a liar? Am Psychol. 1991; 46: 913-920.

5. Elaad E. Effects of feedback on the overestimated capacity to detect lies and the underestimated ability to tell lies. Applied Cognitive Psychology. 2003; 17: 349-363.

6. Elaad E. Lie-detection biases among male police interrogators, prisoners, and laypersons. Psychol Rep. 2009; 105:1047-1056.

7. Elaad E, Lavy S, Cohenca D, Berholz E, Thee P, and Ben-Gigi Y. Lies, truths, and attachment orientations in late adolescence. Personality and Individual Differences. 2012; 52: 670-673.

8. Elaad E. Effects of feedback on self-assessed and actual abilities to tell lies. In: Hasselm AE. editor. Crime: Causes, Types and Victims. Hauppauge (NY): Nova Science Publishers. 2011. pp. 155-166.

9. Gilovich T, Savitsky K, Medvec VH. The illusion of transparency: biased assessments of others’ ability to read one’s emotional states. J Pers Soc Psychol. 1998; 75: 332-346.

10. Tversky A, Kahneman D. Judgment under Uncertainty: Heuristics and Biases. Science. 1974; 185: 1124-1131.

11. .Kaplar ME, Gordon AK. The enigma of altruistic lying: Perspective differences in what motivates and justifies lie telling within romantic relationships. Personal Relationships.2004; 11: 489-507.

12. Vrij A. Detecting lies and deceit: Pitfalls and opportunities, 2nd Ed. Chichester UK: Wiley; 2008..

13. Stromwall LA, Granhag PA, and Hartwig M. Practitioners’ beliefs about deception. In PA Granhag and LA Stromwall, (Eds.), The Detection of Deception in Forensic Contexts. Cambridge UK: Cambridge University Press; 2004; 229-250.

14. Kassin SM. On the psychology of confessions: does innocence put innocents at risk? Am Psychol. 2005; 60: 215-228.

15. Kassin SM, Goldstein CC, Savitsky K. Behavioral confirmation in the interrogation room: on the dangers of presuming guilt. Law Hum Behav. 2003; 27: 187-203.

16. Kohnken G. (1989). Behavioral correlates of statement credibility: Theories, paradigms and results. In H Wegener, F Losel, and J Haisch (Eds.), Criminal behavior and the justice system: Psychological perspectives. New York: Springer-Verlag. 271-289.

17. Perillo JT, Kassin SM. Inside interrogation: the lie, the bluff, and false confessions. Law Hum Behav. 2011; 35: 327-337.

18. Williams EF, Gilovich T. Do people really believe they are above average? Journal of Experimental Social Psychology, 2008; 44: 1121- 1128