Les délinquants sexuels sadiques sont généralement décrits comme une entité clinique particulière commettant des délits graves. Or, la notion même de sadisme sexuel pose un nombre important de problèmes. Parmi ceux-ci, on retrouve des problèmes de validité et de fidélité. Perçu comme une maladie dont on est atteint ou pas, le sadisme a été étudié comme si les sadiques étaient fondamentalement différents. À l’heure actuelle, plusieurs travaux laissent croire que la majorité des troubles psychologiques se présentent comme une différence d'intensité (dimension) plutôt qu’une différence de nature (taxon). Même si la conception médicale prévaut encore en ce qui concerne le sadisme sexuel, plusieurs évoquent l’idée qu’il pourrait être mieux conceptualisé à l’aide d’une approche dimensionnelle. En parallèle, nos connaissances sur les facteurs contributifs au développement du sadisme sexuel sont limitées et reposent sur de faibles appuis empiriques. Jusqu'à présent, très peu d'études se sont intéressées aux facteurs menant au développement du sadisme sexuel et encore moins ont tenté de valider leurs théories. En outre, nos connaissances proviennent majoritairement d'études de cas portant sur les meurtriers sexuels, un sous-groupe très particulier de délinquants fréquemment motivé par des intérêts sexuels sadiques. À notre connaissance, aucune étude n'a proposé jusqu'à présent de modèle développemental portant spécifiquement sur le sadisme sexuel. Pourtant, l'identification de facteurs liés au développement du sadisme sexuel est essentielle dans notre compréhension ainsi que dans l'élaboration de stratégie d'intervention efficace. La présente thèse s'inscrit dans un contexte visant à clarifier le concept de sadisme sexuel. Plus spécialement, nous nous intéressons à sa structure latente, à sa mesure et à ses origines développementales. À partir d'un échantillon de 514 délinquants sexuels évalué au Massachusetts Treatment Center, la viabilité d’une conception dimensionnelle du sadisme sexuel sera mise à l’épreuve à l'aide d'analyses taxométriques permettant d'étudier la structure latente d'un construit. Dans une seconde étape, à l'aide d'analyses de Rasch et d'analyses appartenant aux théories de la réponse à l'item à deux paramètres, nous développerons la MTC Sadism Scale (MTCSS), une mesure dimensionnelle du sadisme sexuel. Dans une troisième et dernière étape, un modèle développemental sera élaboré à l'aide d'équations structurales. La présente thèse permettra de contribuer à la clarification du concept de sadisme sexuel. Une clarification de la structure latente et des facteurs développementaux permettra de saisir les devis de recherche les plus à même de capturer les aspects essentiels. En outre, ceci permettra d'identifier les facteurs pour lesquels une intervention est la plus appropriée pour réduire la récidive, ou la gravité de celle-ci. / Sadistic offenders are generally described as a particular clinical entity committing serious offenses. However, the very notion of sexual sadism is plague with a significant number of problems. Among these, there are important problems of validity and reliability. Perceived as a disease which one can or can't have, sadism was studied as if sadistic offenders were fundamentally different from non-sadistic offenders. Actually, several studies suggest that the majority of psychological disorders present a dimensional rather that a taxonic structure. Therefore, the difference between two individuals will be a difference of intensity instead of nature. Although the medical conceptualization still prevails regarding sexual sadism, many evoke the idea that it might be best conceptualized using a dimensional approach. On the other hand, our knowledge on the factors leading to the development of sexual sadism are based on weak empirical foundations. So far, very few studies have examined the factors leading to the development of sexual sadism and even fewer have attempted to validate their theories. In addition, our knowledge mainly comes from case studies of sexual murderers, some of whom exhibit an extreme form of sexual sadism. To our knowledge, no study has proposed a developmental model of sexual sadism. The identification of factors associated with the development of sexual sadism is essential in our understanding of this paraphilia and in the development of effective intervention strategies. The aim of the present thesis is to clarify the concept of sexual sadism. Specifically, we are interested in its latent structure, its assessment and its developmental origins. From a sample of 514 sexual offenders assessed at the Massachusetts Treatment Center, the viability of a dimensional conception of sexual sadism will be tested using taxometrics analyses. In a second step, using Rasch analyses and two-parameters item response theory analyses, we will develop the MTCSS, a dimensional measure of sexual sadism. In a third and final stage, a developmental model of sexual sadism will be developed using structural equations analyses. The current thesis will contribute significantly to the clarification of the concept of sexual sadism. A clarification of its latent structure and developmental factors will allow to develop better research designs to capture the essential aspects of sexual sadism. In addition, this will allow to identify the factors for which intervention is the most appropriate to reduce recidivism, or the severity of it.

The past two decades have seen a surge of research publications in the psychology of religion, with most studies affirming the salutary effects afforded by religious functioning. However, current mental health researchers have advocated for more nuanced examinations of religious constructs and more careful analysis of potentially harmful aspects of religiosity. Particularly absent from the psychological literature are the mental health effects religious beliefs may exert on parishioners. Researchers note that this is surprising given the general psychological tenet that beliefs are inextricably bound-up with affective states and general mental health. Responding to the admonition of researchers in the field, this study proposes and tests an initial model of psycho-spiritual abuse. The proposed model of psycho-spiritual abuse hypothesizes that religious beliefs such as the theological doctrine of original sin, fundamentalist ideology, lack of self-forgiveness, and negative God-representations, in addition to familial upbringing, may negatively impact an individual’s view of self, thus fostering psychological distress. In particular, this study considers scrupulosity disorder, depression, and shame to be the primary psychiatric maladies engendered by psycho-spiritual abuse. Two hundred thirty five parishioners from 18 Christian faith groups across the United States participated in an online survey consisting of standardized measures of original sin, fundamentalism, self-forgiveness, god image, perceived parental rearing, scrupulosity, depression, and shame. A canonical correlation analysis was conducted because it allows for the simultaneously testing of the relationship between the criterion variables (i.e., scrupulosity, depression, and shame) and predictor variables (i.e., original sin, religious fundamentalism, self-forgiveness, parental rearing perceived as rejecting, emotionally warm, and overprotective, as well as accepting, presence, and challenging God-representations) of interest. Results reveal that greater degrees of belief in the theological doctrine of original sin as well as greater adherence to religious fundamentalist ideologies are directly and indirectly associated with scrupulous and depressive symptomatology as well as with shame-prone feelings and actions in unhealthy ways. Results also indicate that God-representations also play an essential role in scrupulosity, depression, and shame in hypothesized ways. Hence, such results further implicate the centrality of religious ideologies in the expression of psychopathology. Additionally, results seem to suggest that the direct familial contribution to the expression of psychopathology among parishioners appears to be weaker (i.e., secondary) than that of religious beliefs; this statement is based on the fact that perceived parental rearing practices were secondary contributors to the synthetic variable of psycho-spiritual beliefs in both Function 1 and 2. Finally, these results suggest that the primary mechanism through which religious beliefs as well as familial upbringing impact parishioner psychological well-being is the resulting view of the self they engender. Therefore, results suggest that the proposed model of psycho-spiritual abuse is sound. / text