In the past few years, the interest in the constructs of humility and narcissism has been increasing because of unhumble manager behaviour and the appearance of Donald Trump. Consequently, researchers have been investigating the influence of leader’s and followers’ humility and narcissism in the work context. Nevertheless, previous research used self-reports of humility and did not consider facets of narcissism, thus presenting drawbacks of earlier studies. Keeping this in mind, the dissertation focuses on these two personality traits and examines their effect on the leader-follower interaction and follower performance. The leader-follower interaction is assessed by the leadership behaviour perceived by the followers and relationship conflict between the leader and the follower. With regard to follower performance, the focus is on followers’ extra-role behaviour including follower voice behaviour and Organizational Citizenship Behaviour (OCB). In Chapter 2, the influence of leader’s implicit humility on leadership behaviour is investigated. The humility measurement paradox describes that humble people do not indicate their humbleness when asked directly and vice versa. Therefore, an Implicit Association Test (IAT) of humility is developed to assess a leader’s true humility. The results from a multi-source multi-wave field study with 250 leader-follower dyads show that implicit leader humility predicts humble leadership behaviour, abusive supervision and followers’ trust in leader, whereas explicit (i.e., self-reported) humility does not. These findings show that measurement aspects are of critical importance when assessing personality characteristics such as humility that might be prone to socially desirable responding. Therefore, the use of an IAT of humility might present a solution to the humility measurement paradox by avoiding problems associated with the use of explicit measures of humility. The results also suggest that genuine humility is a valuable personality trait of a leader. Personality traits such as extraversion and dominance have been associated with an effective leader in the past. These findings, however, point to the leader’s humility as a valuable trait of a leader. Chapter 3 focuses on follower narcissism and its influence on follower empowerment and follower voice behaviour, which describes the expression of constructive challenge in order to improve rather than to criticise. Based on the Narcissistic Admiration and Rivalry Concept, two facets of narcissism are assessed. Narcissistic rivalry represents the dark side of narcissism. Contrary to that, narcissistic admiration describes the bright side of narcissism. In a multi-source multi-wave field study with 268 leader-follower dyads, follower narcissistic rivalry negatively influences follower empowerment and in turn voice, whereas narcissistic admiration has a positive effect. Moreover, two moderators, leaders’ implicit followership theories and followers’ promotion focus are examined. When leaders have a positive view towards their followers and think that their followers are in general productive and loyal, the negative effect of follower narcissistic rivalry on empowerment is attenuated. Similarly, this effect is also damped when the follower has a high promotion focus. The analysis of follower narcissism reveals that a sophisticated point of view is necessary when investigating the influence of follower narcissism on work outcomes. The results show that narcissism should not be considered globally. Instead, the differentiation of facets seems reasonable to identify both negative and positive effects of narcissism that are present. Chapter 4 deals with the question what might happen if both leaders and followers are high on narcissism. Again, different facets of narcissism are considered. The interaction of leader and follower narcissism is considered in the prediction of relationship conflict and OCB, which is a behaviour beneficial for an organization and not explicitly described in the formal job description. In a multi-source field study with 104 leader-follower dyads, follower narcissistic rivalry positively predicts relationship conflict and in turn negatively affects OCB, whereas follower narcissistic admiration did not lead to conflict and OCB. The Narcissistic Leaders and Dominance Complementarity Model (Grijalva & Harms, 2014) argues that submissive followers are on good terms with narcissistic (dominant) leaders. Based on this complementarity, it was suggested that narcissistic followers should not get along with their narcissistic leaders when both of them are high on narcissistic rivalry. The results showed that if both leader and follower are high on narcissistic rivalry, relationship conflict is strengthened. Other combinations of leaders’ and followers’ narcissistic facets do not enhance relationship conflict.
