Martijn van Teffelen

General introduction 15 1 PURPOSE AND OUTLINE OF THE DISSERTATION This dissertation is focused on the examination of the validity of hostility and how to manipulate it. There are three main goals. First, we aimed to investigate the dimensional structure of hostility. Second, we compared laboratory methods that provoke hostility and studied how they interact with the personality traits of psychopathy and narcissism. Third, we attempted to develop new ways to advance treatment options for hostility. With this dissertation we hope to contribute to a better understanding of the hostility construct, and of the differential effects of laboratory provocation methods, and advance treatment options for hostility. In chapter 2 we examine the dimensions of hostility. More specifically, we examine the hierarchical structure of hostility in a mixed community and highly hostile sample. This is relevant because previous work shows differences in number and content of structural solutions. The main expectation is that a multidimensional hierarchical structure will be uncovered. Chapter 3 focuses on the head-to-head comparison of two laboratory provocation procedures in a male community sample: social exclusion and insult. This is relevant because previous work neglected the differential impact of provocation methods on hostility and their relationship with psychopathic and narcissistic personality traits. We expect that social exclusion and insult were comparable in terms of perceived threat, negative affective change, and aggressive behavior. We also expect that the relationship between psychopathic traits and provoked aggressive responding will be dampened by reduced affective responding. We furthermore hypothesize that narcissistic traits are positively associated with perceived threat, especially after being insult. In turn, we hypothesize that narcissistic traits are positively associated with aggressive responding (i.e., moderated mediation). New ways to enhance treatment options for hostility are presented in chapter 4 , 5 , and 6 . In chapter 4 we aim to compare the efficacy of one session ‘imagery-enhanced CR’ (I-CR) for hostility with traditional CR and an active control (AC) condition at pre- and post-intervention and at one-week follow-up in a sample with increased hostility levels. We hypothesize that I-CR is more efficacious than traditional CR in primarily reducing the believability of hostile cognitions and secondarily reducing aggressive inclinations, state anger and hostility traits, while both interventions are expected to be more efficacious on these variables than an active control condition. These hypothesized condition differences are expected to be maintained when participants are ‘provoked’ by imaginarily re-exposing them to an idiosyncratic anger- provoking situation at one-week follow-up. Chapter 5 provides a narrative description of the I-CR intervention, including case examples to stimulate implementation of this technique in clinical practice.