The aim of this dissertation was to examine the potential “dark side” of leaders’ narcissism, especially with regard to destructive leader behavior and its effects on followers. Leadership is highly relevant for organizational and individual outcomes (e.g., Barrick et al., 1991; Judge & Piccolo, 2004; Harter et al., 2002; Wang et al., 2011) and leader personality traits are meaningful predictors for leaders’ behavior and leadership styles (e.g., Dulebohn et al., 2012; Judge et al., 2002). Whereas leaders’ narcissism has previously been suggested as a potentially destructive leader personality trait (e.g., Krasikova et al., 2013), empirical evidence regarding the effects of leaders’ narcissism in organizations has been inconclusive to date (for overviews, see Braun, 2017 or Schyns et al., 2019). With the empirical studies conducted in the context of this dissertation, I aimed to shed light on the questions whether leaders’ narcissistic rivalry is a precursor of abusive supervision, which cognitive processes might underlie this relationship and whether followers can have an influence on their leaders’ potentially destructive behavior. Furthermore, I set out to examine the effects of leaders’ narcissistic rivalry on their followers and took a closer look on how this maladaptive narcissism dimension affects followers’ feelings, behavior and their mutual relationships. This dissertation expands and contributes to the literature at the intersection of personality and leadership research in several ways. For one, I based my research on a two-dimensional conceptualization of subclinical narcissism. Previous studies mainly framed or at least measured leaders’ narcissism as a unidimensional construct (see Back & Morf, 2018), thereby potentially intermingling adaptive and maladaptive aspects. In this dissertation, in contrast, I used the narcissistic admiration and rivalry concept (NARC; Back et al., 2013) as a theoretical foundation and focused on the relevance of narcissistic rivalry, the antagonistic narcissism dimension, in a leadership context. Narcissistic rivalry in the framework of the NARC is characterized by self-defensive strategies aimed at protecting the narcissists’ inflated ego from potential threats. It is associated with devaluation of others in order to elevate oneself, with aggressive and manipulative behavior and social conflicts (Back et al., 2013). In consequence, I examined whether leaders’ narcissistic rivalry predicted abusive supervision or abusive supervision intentions as one instantiation of destructive leadership. Second, I aimed to shed light on the mechanisms connecting leaders’ narcissistic rivalry and abusive supervision. The NARC proposes that narcissistic rivalry is associated with derogative cognitions about others (Back et al., 2013). By belittling their followers and evaluating them negatively, leaders high in narcissistic rivalry could bolster their own egos. Furthermore, based on ego threat theory (Baumeister et al., 1996) and the NARC, one could assume that leaders act abusively towards their followers in reaction to perceived ego threats. Individuals high in narcissism react aggressively to negative feedback (Bushman & Baumeister, 1998; Ferriday et al., 2011; Kernis & Sun, 1994) and abusive behavior towards one’s followers could be used as a means to regain status and reassert one’s authority over others (Grapsas et al., 2019). Thus, I aimed to understand whether leaders’ devaluing cognitions about their followers and perceived ego threats could explain the assumed positive relationship between leaders’ narcissistic rivalry and destructive leadership. Third, leadership of course does not happen in a vacuum but is a dyadic phenomenon, shaped by both leaders and followers (e.g., Shamir, 2007). It has been shown that how followers behave and are perceived by their leaders can contribute to destructive leadership (e.g., Mawritz et al., 2017; Neves, 2014). However, studies on the interplay between leaders’ “dark” personality traits and follower behavior are still scarce, even though the NARC proposes that self-defensive strategies are potentially triggered in social situations where narcissistic individuals do not receive the admiration they feel they are entitled to and their grandiose, but fragile egos are threatened (Back et al., 2013; Geukes et al., 2017). Consequently, I also scrutinized follower behavior as a potential trigger for abusive leader behavior and for underlying mechanisms that might promote such behavior. Fourth, and lastly, I took a closer look at how followers are affected by leaders’ narcissistic rivalry as a potentially harmful leader trait. The NARC proposes that individuals high in narcissistic rivalry tend to show destructive behavior in interpersonal situations (Back et al., 2013). Based on social exchange theories (e.g., Cropanzano & Mitchell, 2005; Graen & Uhl-Bien, 1995) one would expect that followers reciprocate with negative attitudes and behavior in the workplace when they perceive their leaders to be unsupportive or even abusive. Thus, I asked whether followers of leaders high in narcissistic rivalry felt supported by their leaders and how they evaluated their mutual relationships. Also, I examined whether leaders’ narcissistic rivalry had an influence on followers’ job engagement and performance-based self-esteem, both of which are predictors for important organizational and individual outcomes such as motivation, well-being and performance (e.g., Dulebohn et al., 2012; Judge et al., 2007). These research questions were examined in four empirical studies applying different research designs, which are reported in the three manuscripts that compile this dissertation (Chapters 2-4). In the first manuscript (Chapter 2), I hypothesized that leaders’ narcissistic rivalry would predict abusive supervision intentions and that this positive relationship would be moderated by follower behavior. Based on theoretical assumptions drawn from ego threat theory (Baumeister et al., 1996) and the dominance complementary model (Grijalva & Harms, 2014), I assumed this relationship to be stronger when followers behaved dominantly compared to constructive or submissive behavior. Furthermore, I examined potential cognitive mechanisms underlying the association between leaders’ narcissistic rivalry and abusive supervision intentions. Specifically, I proposed that the assumed positive relationship would be mediated by leaders’ evaluations of their followers as unlikeable and incompetent. The assumptions were tested in an experimental vignette study with a real-life leader sample. Leaders’ narcissistic rivalry positively predicted abusive supervision intentions in response to submissive, constructive and dominant follower behavior. The relationship was strongest when followers in the experimental vignettes behaved dominantly. Concerning the underlying cognitive mechanisms, I found preliminary evidence that leaders’ evaluations of followers as unlikeable, but not as incompetent, mediated the association between narcissistic rivalry and abusive supervision intentions. In the second manuscript (Chapter 3), I again hypothesized that leaders’ narcissistic rivalry would predict abusive supervision intentions (Study 1) or abusive supervision (Study 2). Assuming that leaders high in narcissistic rivalry easily perceive their grandiose, but fragile egos to be threatened in social interactions (Back et al., 2013; Geukes et al., 2017), I posited an indirect effect of leaders’ narcissistic rivalry on abusive supervision intentions or abusive supervision via perceived ego threat, and a moderation of this indirect effect by followers’ supervisor-directed deviance. I predicted that this indirect effect would be stronger, the more supervisor-directed deviance followers showed, as such behavior could be perceived as undermining a leader’s status and thus challenge their grandiose self-view. These assumptions were tested in an experimental vignette study with leaders (Study 1) and in a field study with leader-follower dyads (Study 2). Across both studies, leaders’ narcissistic rivalry was positively related
