Nous sommes tous familiers avec les notions de tromperie et de détection du mensonge Nous admettons volontiers que mentir n’est pas un acte acceptable moralement. Le mensonge a toujours posé un problème moral. Par exemple, Aristote disait que « le mensonge est en soi méchant et coupable », Kant considérait la vérité comme un « devoir inconditionnel en toutes circonstances ». Machiavel a adopté une position différente en louant le mensonge au service de soi. Après avoir été un problème moral et juridique pendant des millénaires, la question du mensonge et de sa détection est devenue depuis une soixantaine d’années une question de recherche. Comment les gens réussissent-ils à tromper les autres ? Comment sont-ils susceptibles de croire les mensonges des autres ? Sont-ils capables de détecter lorsque quelqu’un leur ment ? Si oui, comment ? Pourquoi les gens sont-ils dupés ? Ces questions sont toujours d’actualité et cette thèse s’inscrit dans la continuité des recherches sur la détection du mensonge, dans le cadre de la détection sans instruments spécialisés.Les parutions scientifiques issues de la littérature sur la capacité humaine de détection du mensonge sont pessimistes et montrent que les individus font rarement mieux que le hasard. Si des explications ont été apportées, de nombreuses interrogations persistent encore, comme l’influence de certains aspects de la personnalité et de la cognition sur la capacité à détecter les mensonges. Nous avons ainsi mené plusieurs études expérimentales dans le but de répondre à certaines questions encore présentes. L’ensemble de nos résultats suggèrent que les traits de personnalité associés à une sensibilité aux émotions des autres nuisent à la bonne détection du mensonge. Nos résultats montrent, pour la première fois, que des fonctions cognitives, comme la reconnaissance de la prosodie, l’attention et la compréhension du discours sont impliquées dans la détection du mensonge. Enfin, ce travail de thèse a également examiné si des aspects de la personnalité et de la cognition influencent la capacité de détection de membres des forces de l’ordre. / We are all so familiar with the notions of deception and lie detection. We readily admit that lying is not morally acceptable. Lying has always been a moral problem. For example, Aristotle said that "falsehood is in itself mean and culpable" or Kant regarded the truth as "unconditional duty which holds in all circumstances.” Machiavelli has taken a different position by praising deceit in the service of self. After having been a moral and legal problem for millennia, the question of lies and their detection has become a question of research for about sixty years. How do people deceive others? How are people likely to believe the lies of others? Are they able to detect when someone is lying to them? And if yes, how? Why are people fooled? These questions are still relevant, and this thesis is part of the continuity of research on the detection of lies, in the context of detection without a specialized instrument.Scientific publications from the literature on the human capacity to detect lies are pessimistic and show that individuals rarely do better than chance. If explanations have been made, many questions still persist, such as the influence of certain aspects of personality and cognition on the ability to detect lies. We have conducted several experimental studies to answer some of the questions. All of our results suggest that personality traits associated with sensitivity to the emotions of others interfere with the capacity to detect lies. Our results show, for the first time, that cognitive functions, such as recognition of prosody, attentional processes and discourse comprehension, are involved in the detection of lies. Finally, this thesis also examined whether aspects of personality and cognition influence the detection ability of police officers (French Gendarmes).

In recent years cognitive methods for lie detection has appeared. This with an increased need for digital tools for aiding professionals in the pursuit of detecting deceit. This study attempts to build and test a software agent to see if it can detect lies using reaction time (RT). In extension to this the study also asked which strategy would be best to find an unknown item if the agent was able to detect lies. 21 participants (mean age 30) were gathered online by the means of a link to a webpage with the software agent and a card prediction game on it. The study can thereby be viewed as a correlation study in the category of human computer interaction. The procedure was that the software agent would try to predict a card shown to the participant by asking questions. But the participant would try to deceive the software agent and make it fail. The participant was also instructed to answer as quickly as possible. The participant would do this while mixing truths and lies. The result of the study was that the software agent was unable to learn to distinguish between truths and lies using RT. It could therefore not be established what could have been an appropriate strategy. But an interesting finding might have been made. As the results suggest that it might be better to ignore truth as a category and instead use the RT of the task itself as the comparison for if the participant was lying. / Denna studie testade att använda en mjukvare agent för att upptäcka lögner med hjälp av reaktionstid (RT). Studien försökte även svara på vilken strategi som skulle vara optimal för att hitta ett okänt objekt ifall mjukvare agenten lyckades förutse ifall en människa ljuger. Studien hade 21 deltagare (medelålder 30 år). Dessa deltagare blev samlade online och utförde experimentet från sina hemdatorer utan översikt. Experimentet var en korrelationstudie där mjukvare agenten försökte förutse ett kort från en standard kortlek som visats för deltagaren. Därefter så skulle deltagaren svara så snabbt som möjligt på datorns frågor genom att klicka på tangentbordet. Detta medan deltagaren blandade att svara sant eller falskt. Resultatet var att mjukvare agenten förblev oförmögen att kunna förutse ifall en människa ljög eller inte. Därav bekräftades ej studiens frågeställningar. Men ett intressant fynd kan ha upptäckts. Resultatet pekar på att det kan vara bättre att använda sig av RT för handlingen istället för RT för sanning för att upptäcka ifall någon ljuger.

This dissertation thesis called 'Lie Detection Through Verbal and Nonverbal Behavior' deals with lying and lies from the viewpoint of its types, functions and considering the development of an individual and it describes the role of lying in our lives. Lying itself is not considered as a negative term, but as a type of communication, a social phenomenon, which is a part of our everyday existence. Attention is aimed to verbal behaviour, but especially to nonverbal aspects of lying persons. Then it examines the use of information on lying and lies in the system of forensic psychology during the deception detection tests. It describes historical approaches to lie detection and its current appearance as well as some other aspects, that may be considered lying even if they are not lying at all - false memories or suggestions. The empirical part compares two research designs, one of them trying to find possible personal determinants of successful lie detectors on a group of psychology students and connecting lie detection ability with the concept of emotional inteligence. The second research analyzes the ability to detect deception among Czech police officers as a specific population group, that uses lie detection methods as a means of investigation. Keywords: lying, deception detection, nonverbal...

La psychopathie est souvent associée à tort comme un trouble se retrouvant exclusivement chez des criminels alors que jusqu’à 8 % de la population générale pourrait présenter des traits psychopathiques élevés. Récemment, nous observons un essor de recherches tentant d’appliquer des théories évolutionnistes, telles que la sélection naturelle, à des processus psychologiques et à la personnalité. Des théoriciens de la psychologie évolutionniste se sont penchés sur la prévalence considérable de la psychopathie dans la population générale et tentent de l’expliquer par le caractère adaptatif de ses traits chez ses individus. Les caractéristiques de la psychopathie comme une faible empathie, une tendance à la manipulation, aux mensonges et à l’impulsivité pourraient leur permettre de profiter du reste de la société et ainsi s’approprier différentes ressources. De plus, leur capacité à faire abstraction des émotions pourrait leur conférer un avantage quant à la détection du mensonge, notamment dans des situations à haute teneur émotionnelle. Cette thèse vise à présenter une revue de la littérature à jour des différentes théories évolutionnistes expliquant la psychopathie comme étant une forme d’adaptation à l’environnement. En outre, elle cherche à évaluer la relation entre la détection du mensonge et les traits psychopathiques, en remédiant à plusieurs lacunes méthodologiques des études précédentes. En nous inspirant des différentes théories évolutionnistes explicatives de la psychopathie et de Lyons et al. (2013), nous avons émis l’hypothèse que les traits psychopathiques permettraient une meilleure détection du mensonge à haute teneur émotionnelle et que cette relation serait plus marquée chez les hommes que chez les femmes. Pour tester ces hypothèses, nous avons recueilli les réponses de 504 participants, composés de 333 femmes (65,9 %) et de 163 hommes (32,4 %) provenant de la population générale. Les résultats indiquent qu’il n’y avait pas de lien entre l’intensité des traits psychopathiques et la capacité à détecter un mensonge lorsque l’âge ainsi que le genre des participants étaient contrôlés. Cependant, les traits psychopathiques étaient associés à une meilleure détection spécifique du mensonge et à une moins bonne détection spécifique de la vérité. En d’autres termes, les traits psychopathiques semblent être liés à une perception accrue de mensonge de façon générale. Aucun effet modérateur n’a été identifié en fonction du genre des participants. Toutefois, une relation négative entre la détection du mensonge et les traits psychopathiques a été observée chez les femmes, tandis qu’aucune relation n’a été constatée chez les hommes. Nos résultats ne contredisent pas les théories évolutionnistes sous-tendant nos hypothèses initiales. Au contraire, la perception d’autrui comme étant malhonnête et menaçant peut être considéré comme un avantage lorsqu’elle est associée aux caractéristiques propres à la psychopathie. Cette thèse contribue à éclaircir le lien entre la psychopathie et la détection du mensonge, tout en permettant de contribuer empiriquement à différentes théories évolutionnistes. / Psychopathy is often mistakenly associated with criminality, while up to 8 % of the general population may exhibit elevated psychopathic traits. Recently, there has been a surge in research attempting to apply evolutionary theories, such as natural selection, to psychological processes and personality. Evolutionary psychologists seek to explain the prevalence of psychopathy in the general population through the adaptative nature of its traits in individuals. Characteristics of psychopathy such as low empathy, a tendency for manipulation, lying, and impulsivity may enable individuals to exploit the rest of society and appropriate various resources. Additionally, their ability to disregard emotions could provide an advantage in detecting deception, particularly in high-emotion situations. The present thesis aims to provide an up-to-date literature review on different evolutionary theories explaining psychopathy as an adaptation to the environment. Furthermore, it seeks to demystify the relationship between deception detection and psychopathic traits by addressing several methodological limitations of previous studies. Drawing inspiration from evolutionary theories of psychopathy and Lyons et al. (2013), we hypothesized that psychopathic traits would facilitate detection of high-emotion deception, with this relationship being more pronounced in men than in women. To test these hypotheses, we collected data from 504 participants, consisting of 333 females (65.9 %) and 163 males (32.4 %) from the general population. The results indicate no association between the intensity of psychopathic traits and the ability to detect deception when controlling for age and gender of participants. However, psychopathic traits were associated with better specific deception detection and poorer specific truth detection. In other words, psychopathic traits appear to be linked to an overall heightened perception of deception. No moderating effects were identified based on participants' gender. However, a negative relationship between deception detection and psychopathic traits was observed among women, while no relationship was found among men. Our results are not contradictory to the evolutionary theories underlying our initial hypotheses. Rather, perceiving others as dishonest and threatening can be considered an advantage when combined with characteristics inherent to psychopathy. This thesis contributes to a better understanding of the link between psychopathy and deception detection, while empirically contributing to various evolutionary theories.

This research paper has examined the validity of the Forensic Assessment Interview Technique (FAINT). FAINT is a specific interview process - accepted and in current use - integrating the works of this researcher with the works of John Reid, Richard Arther, and Avinoam Sapir. The FAINT technique involves the evaluation of nonverbal behavior, projective analysis of unwitting verbal cues, and statement analysis. The fundamental hypothesis of FAINT is that truthful and deceptive criminal suspects differ demonstrably in their nonverbal, verbal and written communication, when asked to respond to a structured format of interview questions. FAINT maintains that these differences are observable and can be quantified to allow forensic interviewers to make accurate determinations of a suspect's involvement in a crime. This research has examined the validity of the technique as measured by a traditional, unweighted 3 point scale and a weighted scoring system (an issue being researched in this paper) comparatively used for determining truth or deception. This dissertation reports the results of both scoring systems, as well as a comparison between them and the historically used Behavioral Analysis Interview (BAI) that was developed by John E. Reid. / Criminology / MA (Criminology)

This research paper has examined the validity of the Forensic Assessment Interview Technique (FAINT). FAINT is a specific interview process - accepted and in current use - integrating the works of this researcher with the works of John Reid, Richard Arther, and Avinoam Sapir. The FAINT technique involves the evaluation of nonverbal behavior, projective analysis of unwitting verbal cues, and statement analysis. The fundamental hypothesis of FAINT is that truthful and deceptive criminal suspects differ demonstrably in their nonverbal, verbal and written communication, when asked to respond to a structured format of interview questions. FAINT maintains that these differences are observable and can be quantified to allow forensic interviewers to make accurate determinations of a suspect's involvement in a crime. This research has examined the validity of the technique as measured by a traditional, unweighted 3 point scale and a weighted scoring system (an issue being researched in this paper) comparatively used for determining truth or deception. This dissertation reports the results of both scoring systems, as well as a comparison between them and the historically used Behavioral Analysis Interview (BAI) that was developed by John E. Reid. / Criminology and Security Science / MA (Criminology)

This study examined the ability of students to correctly discern between truthful and deceptive messages from a group of second language English speakers. Recent studies have found a ‘lie bias’ when making veracity judgments towards second language speakers. This lie bias may be problematic in a country such as South Africa where the majority of the population communicate, to a greater or lesser extent, in their second language. In this study participants (n=64) made classifications of 24 messages as either truthful or deceptive. The messages were created by second language English speakers who were asked to describe a truthful or deceptive event. The results revealed that there was a significant difference between the way that first and second language participants made their judgments. It is argued that this difference can be attributed to the notion that second language participants require more cognitive effort, than their first language counterparts, to understand and classify messages. / Psychology / M. A.(Psychology)