Kumulative Dissertation, Otto-Friedrich-Universität Bamberg, 2025

Von der genannten Lizenzangabe ausgenommen sind folgende Bestandteile dieser Dissertation:

Study 1 "Servant and crisis manager? The association of servant leadership with followers’ adaptivity and proactivity" (S. 14-51) und Study 2 "Trajectories and associations of perceived servant leadership and teacher exhaustion during the first months of a crisis" (S. 52-86) stehen unter der CC-Lizenz CC-BY.
Lizenzvertrag: Creative Commons Namensnennung 4.0
https://creativecommons.org/licenses/by/4.0/

In recent years, there has been increasing interest in the concept of servant leadership, as studies have shown a large variety of positive results. This dissertation aims to enhance the understanding of the relationship between servant leadership and follower behaviors and experiences. To this end, I present three empirical articles that focus on the associations of servant leadership with follower performance and well-being and the methods used to examine the leadership construct as an explanatory variable. Because research on servant leadership has been conducted mostly without contextualization, Studies 1 and 2 explore whether servant leadership is also beneficial in the still underresearched crisis context. Specifically, Study 1 investigates the associations between servant leadership perceptions and followers’ performance (i.e., adaptivity and proactivity) and delves into mediating mechanisms between the constructs. Study 2 takes a dynamic perspective and focuses on the trajectories of and relationship between servant leadership perceptions and follower well-being (i.e., exhaustion) during a crisis. These longitudinal studies have several strengths—however, they should not be causally interpreted. As this is an issue that relates to many studies on servant leadership (and leadership in general), Study 3 deals with the question of whether the effects of servant leadership determined in research so far are robust and what can be done to conduct causally identified studies.
Studies 1 and 2 are based on a longitudinal survey among teachers in a German private school association (N = 129) with four measurement points approximately two months apart. Data collection was conducted during the first eight months of the COVID-19 crisis; the first measurement started in March 2020, when the first measures such as curfews were taken. Still, the two studies are independent as they only overlap regarding perceived servant leadership as an explanatory variable. The path model in Study 1 showed that servant leadership perceptions were related to both followers’ adaptivity and proactivity via basic psychological need satisfaction. There were no direct relationships between servant leadership perceptions and follower adaptivity or proactivity, and there was no indirect association with adaptivity via procedural justice. The mediating relationship between servant leadership perceptions and proactivity was negative. The study indicates that followers’ needs should not be overlooked in the crisis context to help them cope with crises and that servant leadership is an appropriate means to achieve this goal. At the same time, Study 1 points to the potential negative effects of servant leadership on proactivity via procedural justice in certain circumstances.
Based on conservation of resources theory, Study 2 examined the development of the association between servant leadership perceptions and exhaustion during the first eight months of a crisis. Using latent growth curve modeling, the results showed that servant leadership perceptions were both inter- and intraindividually related to followers’ exhaustion. Between-person, a higher level of servant leadership perceptions was associated with a lower level of exhaustion. Within-person, a greater decrease (increase) in servant leadership perceptions was related to a greater increase (decrease) in exhaustion. Additionally, the univariate trajectories of the constructs yielded that servant leadership perceptions decreased over the study period. The decrease slowed from T1 to T3 before servant leadership perceptions increased again between T3 and T4. Teachers’ exhaustion did not increase on average during the first eight months of the crisis. The trajectories of and associations between the constructs are thus complex and can vary over time. Furthermore, the findings suggest that servant leadership is appropriate for reducing the negative effects of crises on followers’ exhaustion.
Study 3 investigated the current state of research regarding causality in the field of servant (and authentic) leadership and provides recommendations on how causally identified studies on these leader behaviors can be conducted to enable researchers to meaningfully inform science and policy. First, endogeneity bias and issues in experimental design are discussed as central problems that can prevent causal inferences from studies on the effects of servant leadership. Then, the current state of research on servant and authentic leadership as explanatory variables is summarized through systematic reviews. The results indicate that the lack of causal examinations is highly prevalent. As guidance in this regard, two ways in which causal research on the effect of servant leadership (perceptions) could be cleanly conducted are described: well-designed randomized experiments and instrumental variable regression. To illustrate the recommendations, an exemplary experiment was conducted using manipulated leader behavior as an instrument for follower perceptions. In this randomized lab experiment, the effect of a combined stewardship and authenticity manipulation, as well as the perceptions thereof, on individual task performance were examined. The experiment did not reveal an effect of either combined stewardship and authenticity behavior or perceptions thereof on performance.
In summary, this dissertation provides first evidence that servant leadership can be beneficial in the crisis context but that it can also have unintended negative effects. Additionally, pitfalls in servant leadership research that severely limit the validity of empirical studies in the field are pointed out. To support the conduction of solid, causally identified research, recommendations to improve research are provided, along with an illustrative experiment. In this way, this dissertation contributes to the state of research on servant leadership in context and over time as well as on its associations with follower performance and well-being and the potential underlying mediating mechanisms of these relationships. Additionally, the presented roadmap can help advance research on servant leadership with robust studies.