Detecting Deception - Lab Report Example

Introduction Humans are deceptive creatures. Arguably more so than other animals, humans have a propensity to lie, cheat, steal, and otherwise deceive their fellow humans. In fact, one study found that 30 to 38% of human interactions contain deception, that 80% of humans lie on resumes, and that 100% of dating couples lie in a least one third of their conversations with their partner (Kornet, 1997) Given this prevalence of deception, it is understandable that humans would also seek reliable means to detect deception in others. Detecting deception has taken a number of forms throughout history with one of the most recognizable being the polygraph machine, otherwise known as the lie detector. These are scientific devices designed to measure a variety of physiological conditions of a subject which are thought to spike suddenly and unconsciously when that subject is being deceptive. However, the administering of even these scientifically-based tests has come under increasing fire. For example, polygraph results were barred from the trial of a U.S. trial of a federal judge as recently as December of 2008 (Assoicated Press, 2008). If such a scientifically-based device has come under such scrutiny and has been routinely barred from legal proceedings, it begs the question of whether an unaided human can detect deception merely by observing the subject. In their 1996 study, Vrij and Semin examined this question by recruiting not only college students, but also subjects from a variety of fields thought to be trained and experienced in lie detection (police patrol officers, prison guards, customs officials, etc.) as well as those constantly exposed to an environment based on lies and deception (prisoners). It was their hypothesis that law enforcement officials would be better at lie detection than "normal people" such as college students and that the criminals would have superior abilities to those of law enforcement. All of the subjects reported that they considered themselves highly experienced at detecting deception (Vrij & Semin, 1996). Vrij and Semin administered their study through a series of questionnaires administered at the subjects' places or work or incarceration. These questionnaires contained questions ranging over 16 nonverbal cues commonly associated with deception and concluded with the subjects rating themselves on their ability to detect deception in others on a 7-point scale. The results were compiled by group (college student, law enforcement, or criminal) and then analysed for accuracy. As predicted, the criminals exhibited the greatest level of accuracy in correctly identifying nonverbal cues of deception. It was also found that there was not a significant difference between the accuracy rates of law enforcement and college students, indicating that those considering themselves professional lie detectors fell victim to the same misconceptions on nonverbal cues as a lay person (Vrij & Semin, 1996). While Vrij and Semin's study does provide useful data that professional lie detectors have no superior knowledge of deceptive nonverbal cues than the rest of us, it does lack in that none of the subjects were actually tested in their ability to detect deception. This study will address that lack by actually testing whether or not subjects can detect deception through nonverbal cues, particularly by focusing on voice pitch. It is predicted that such attention to nonverbal cues will detect deception at a higher rate than chance and that those observers relying on voice pitch as a deceptive cue will be more accurate than observers relying on other nonverbal cues. Methods A pool of 761 subjects was recruited consisting of 454 females and 307 males who were informed that they would be participating in an undergraduate psychology tutorial study. These subjects ranged in age from 17 to 56 years with a mean age of 19.77 years and a standard deviation of 2.58 years. For this study, each subject was instructed to tell a story to another subject. This narrative could either be true or false and the observer was tasked with detecting whether they were being deceived by the speaker. The observers were specifically instructed to watch for nonverbal cues of deception and to use these cues as their means of detecting whether the narrative was truthful or deceptive. These nonverbal cues consisted of eye gaze, voice pitch, and hand movements during the narrative. It was assumed that those observers focusing on voice pitch would be significantly more accurate in their detection of deception than observers focusing on the remaining two nonverbal cues. For the purposes of this study, it was assumed that purely through random chance a given observer would be 50% accurate in identifying truthfulness or deception. To be significant, the observers would need to maintain an accuracy rate above 50%, indicating that their attention to nonverbal cues was providing greater accuracy in detecting deception than they would experience merely by guessing and relying on chance for accuracy. Results When the results were compiled and analysed, it was found that the participants were significantly better at detecting truthfulness than random chance would indicate, achieving an accuracy of 0.64. However, it was also found that the subjects were consistently worse at detecting deception than random chance would allow, maintaining an accuracy of 0.41. It was also found that observing eye gaze and hand movements were not a reliable means of detecting deception, but that focusing on voice pitch did provide a positive correlation on the subjects' ability to detect deception. In other words, as a subject focused more on voice pitch as a nonverbal deceptive cue, their accuracy in detecting deception increased. These results supported the assumption that voice pitch would provide for greater accuracy in the detection of deception, but only partially supported the hypothesis that attention to nonverbal cues would provide a greater accuracy in the detection of deception that what would be encountered merely through random chance. Discussion This study assumed that when humans are deceptive they generate nonverbal cues (eye gaze, voice pitch, and hand movement) that are indicators of that deception. It further hypothesised that by focusing on these nonverbal cues, an observer is able to detect deception with a greater accuracy than guessing and relying on random chance. Finally, it supposed that an observer's attention to voice pitch would provide superior accuracy in detecting deception than relying on other nonverbal cues such as eye gaze or hand movement. While the results do indicate that subjects' attention to nonverbal cues increased their accuracy in detecting a truthful narrative, it also found that the subjects were significantly worse at detecting deception. These results indicate that observers are better at detecting truthful behaviour than they are at detecting deceptive behaviour. One possible explanation is that most persons are simply not trained to effectively detect deception and that they fall victim to popular misconceptions regarding what nonverbal cues are indicative of deceptive behaviour. However, as found by Vrij and Semin, even individuals specifically trained to detect deception such as law enforcement officers who had attended highly specialised police detective courses were no better than the average person at identifying which nonverbal cues were indicative of deception (Vrij & Semin, 1996). With this fact in mind, it is likely that only those who are immersed in a deceptive environment in which they routinely and frequently encounter deception are sufficiently attuned to these nonverbal cues to exhibit any high degree of accuracy in the detection of deception. The work of this study was important in that it actually tested the ability of subjects to detect deception by focusing on nonverbal cues. It also identified voice pitch as a superior nonverbal cue to eye gaze and hand movement during a narrative. Furthermore, it proved that the average subject is statistically superior at detecting truthfulness than they are at detecting deception. However, it was limited in the pool from which it recruited its subjects; not having the ability to recruit prisoners and known criminals who exhibit greater knowledge of deceptive nonverbal cues. While Vrij and Semin have proved that these criminals possess superior familiarity with nonverbal cues that are indicative to deception, they also surmised that this familiarity was gained through living in a criminal environment for an extended period of time (Vrij & Semin, 1996). While interesting, this finding is not particularly useful as even a career police detective is unlikely to want to live in a criminal environment for a protracted time merely to gain advanced knowledge of deceptive nonverbal cues. A future study may wish to examine how the criminal environment imparts its knowledge to criminals and whether or not this knowledge can then be distilled and transferred to other individuals, such as law enforcement officials. This study would need to first identify criminals who do possess a statistical familiarity with deceptive nonverbal cues and then attempt to translate that familiarity to another person, perhaps through coaching or instruction by the criminal. Works Cited Assoicated Press. (2008, December 11). Lie detector tests not admitted at indicted Judge Samuel Kent's trial. Houston News . Kornet, A. (1997). The Truth about Lying. Psychology Today , 53. Vrij, A., & Semin, G. R. (1996). Lie experts' beliefs about nonverbal indicators of deception. Journal of Nonverbal Behavior , 65-80. Read More