Étude internationale : l'effet modérateur d'un trait culturel sur la relation entre les traits psychopathiques et la coopération sociale chez des individus non incarcérés

Psychopathy is characterized by various emotional and behavioural manifestations that include a lack of empathy towards others, manipulation and exploitation. To date, studies of psychopathy have focused primarily on antisocial behaviours, while little attention has been paid to the potential for prosocial behaviours.  Although generally observed in about 10% of the carceral population, psychopathy is also found in the general population. In order to better understand what might distinguish psychopaths adapted to life in society from those involved in criminal activities, some researchers have attempted to study the relationship between psychopathic traits and the ability to cooperate in non-incarcerated individuals. However, the results are inconsistent from one study to another. To date, no research has explored the moderating effect of a third variable, that could potentially explain this discrepancy in data.  For example, some cultural traits, such as individualism versus collectivism, are conceptually linked to both psychopathic traits and social cooperation. The objective of the thesis was to verify the relationship between psychopathic traits and cooperative behaviours among individuals in the general population, while taking into account the effect of participants individualistic or collectivist traits. It was expected that: 1) psychopathic traits would predict uncooperative choices; and 2) this relationship would differ according to the individualistic or collectivist attitudes reported by participants. Recruitment was conducted on the international scene via social networks, classified advertisement sites and some university departments. A total of 134 participants completed the entire study. They completed the following tests in random order: the Levenson Scale of Psychopathy, the Scenarios for the measurement of collectivism and individualism, and an iterative simulation of the prisoner's dilemma involving 12 trials. A hierarchical regression was conducted and did not confirm the hypotheses. Various exploratory analyses were also attempted, including logistic regressions and contrast analyses.  Psychopathic traits were not significantly predictive of cooperative choices in the prisoner's dilemma, nor did the cultural traits have a significant impact on this relationship. An in-depth discussion was conducted to explain these results and to place them in the context of the current scientific literature. More specifically, the Discussion focused on the conceptualization of psychopathic traits and their manifestations in the general population, as well as on research in an intercultural context. A second experiment was conducted with a new sample, correcting the methodological flaws identified in the international study. This second experiment focused on the relationship between psychopathic traits and social cooperation, without considering cultural traits. To improve the research design, only males were recruited, the sample size was increased, and recruitment was not conducted internationally in order to limit variability among participants. Also, a questionnaire measuring the presence of clues to psychopathic traits in childhood and adolescence was added. The objective of this second experiment was to further explore the relationship between psychopathic traits and the adoption of cooperative behaviours in individuals from the general population. Psychopathic traits were expected to be predictors of uncooperative choices. More specifically, the hypothesis was that the more individuals report psychopathic traits in adulthood and psychopathic traits present in childhood, the less likely they are to be cooperative. Recruitment was conducted via social networks. A total of 150 men completed the entire study. Each completed the following tests in random order: the Levenson Psychopathy Scale, the Childhood and Adolescent Taxon Scale-Self Report, and an iterative simulation of the prisoner's dilemma involving 12 trials. Standard and hierarchical multiple regressions were performed. The hypotheses were partially confirmed. Childhood psychopathy indices were predictive of decisions made in the prisoner's dilemma, however the direction of the relationship was not as expected. The results indicated that the higher the score on the Childhood and Adolescent Taxon Scale-Self Report, the more cooperative the individuals were to the prisoner's dilemma.  Second, psychopathic traits in adulthood, as measured by scores on the Levenson Psychopathy Scale, alone did not predict decisions about the prisoner's dilemma. Adult psychopathic traits were predictive of cooperative behaviour only when considered in conjunction with measures of childhood psychopathic trait indicators. The percentage of variance in cooperative behaviour that was explained by the model was small. Also, the predictive value of adult psychopathic traits was entirely attributable to Factor 1 traits (interpersonal and emotional). This time, the relationship was as expected: the higher the score on Levenson's Psychopathy Scale, the less cooperative participants were to the prisoner's dilemma. These results were interpreted in a new Discussion, which shed light on the similarities and differences between the two experiments carried out in the framework of the thesis. Also, questions surrounding the validity of the concept of psychopathy in the general population were supported. Based on the entire thesis, recommendations for future research were formulated.

Keyphrases: Psychopathy, Community, Cooperation, Collectivism, Individualism