The ongoing shift in demographics, marked by declining birth and mortality rates and a shrinking qualified workforce, necessitates that organizations promote health, motivation, organizational commitment, and workability to maintain (older) employees (Chand & Tung, 2014; He et al., 2016; Hertel & Zacher, 2018; Ilmarinen & Tempel, 2002; United Nations Department of Economic and Social Affairs: Population Division, 2022). Thus, the probability of age-diverse teams and the share of older employees in organizations rises (Hertel & Zacher, 2018; Wegge & Schmidt, 2015). While this development can favor employee performance and health (Hertel & Zacher, 2018), managing an age-diverse workforce poses severe challenges for organizations, including suitable ergonomic and personnel measures (Beier, 2015; Deller et al., 2008; Hertel & Zacher, 2018). However, age-diverse teams can negatively impact health and performance if appropriate techniques are not implemented (Joshi & Roh, 2009; van Dijk et al., 2012), such as age-differentiated leadership (Jungmann & Wegge, 2023; J. Wegge et al., 2012). Moreover, the Job-Demand Resources theory (Bakker & Demerouti, 2017; Bakker et al., 2023) describes how demands and resources can affect exhaustion and work motivation. Supervisors may influence these demands and resources on several pathways, such as designing work, performing as a buffer for demands, and acting as a resource for employees, promoting job crafting, and hindering self-undermining (Tummers & Bakker, 2021). In addition, recovery as a self-regulation technique poses another critical factor in the JD-R model (Bakker & de Vries, 2021; Dolce et al., 2020). This dissertation aims to contribute a scientific-based and empirical-examined training approach to improve supervisors' general and age-differentiated leadership behavior as well as the recovery (behavior) of employees and supervisors in various field settings. Furthermore, it adds to training research regarding different contents, target groups, and methods. Studies 1 and 2 had the goal of promoting age-differentiated leadership and positive age-diversity mindsets. However, the age-differentiated training programs used in these studies varied in terms of the target group (large-scale vs. small-scale, one organization vs. various organizations), methods used (web-based vs. face-to-face, trainer vs. no trainer), and length of the training (one-and-a-half vs. two-and-a-half-days vs. required amount to complete the training within 42 weeks). Study 1 was aimed at training supervisors of small- and medium-sized enterprises. The study consisted of Study 1A, which was a one-and-a-half-day face-to-face training (Supervisor sample: N = 74 (warm-up), N = 68 (one-day-training) and N = 47 (booster), subordinates: N = 366 (pre-measurement), N = 115 (post-measurement), N = 55 (matching pre-post measurements), and Study 1B, which was a self-guided web-based training (supervisors: N = 44 (matching pre-post measurement), subordinates: N = 57 (matching pre-post measurements). Based on the beneficial results of Study 1A that displayed, for an example, self-reported increase in subjective knowledge of the training topics, age-differentiated leadership, and age-diversity appreciation, the web-based training was developed. The web-based training also indicated a self-reported increase in subjective knowledge, age-differentiated leadership and age-diversity appreciation. Furthermore, assessments of employees of the trained supervisors showed beneficial tendencies. Based on the supervisor's assessment, several team interaction processes (e.g., team reflexivity) significantly increased, including innovation and team reflection. Thus, findings supported enhanced performance through age-differentiated leadership. Unfortunately, the results were not replicated on the employee or the team level. Nevertheless, non-significant increases in overall age-differentiated leadership and goal-setting were also detected at these levels of analysis. Regarding health, employees also showed non-significant beneficial tendencies. The comparison between the web-based and the face-to-face training yielded no significant differences. However, the web-based version displayed a stronger non-significant increase regarding the measured outcomes (e.g., age-differentiated leadership, age-diversity appreciation). Study 2 conveyed age-differentiated leadership and a positive age-diversity mindset within a two-and-a-half-day training program in a large-scale car manufacturing company. The longitudinal study involved 123 supervisors, and over 800 employees in 90 teams at each of the three measurement times (t1:989, t2: 838, t3: 937). It also looked into the correlation between age-differentiated leadership and break behavior, recovery experiences, and absenteeism. Results indicated a significant self-reported and externally assessed (individual employee level) increase in age-differentiated leadership in the training group compared to the waiting-control group. Effects for age-diversity appreciation and team interaction processes (team identification, conflicts) were not significant. Nevertheless, the training group displayed a more beneficial development. The latter beneficial effects were only detected for innovation on the individual employee level. The study also confirmed the association between age-differentiated leadership with break behavior, recovery after breaks, and recovery behavior. It also supported the expected negative association between age-differentiated leadership and absenteeism. Study 3 investigated a new web-based training for improving break behavior at work and recovery behavior after work in the care sector (N = 17 (pre-post comparison), N = 9 pre- follow-up comparison) over three times of measurement. The training content was derived from a literature review, interviews with care experts, and workshops with care professionals. Supervisors and employees were investigated as one group. Recovery behavior, including recovery planning and behavior, significantly increased. Similarly, a significant improvement in overall recovery experience was detected. In addition, training had a significant positive effect (decrease) on the need for recovery and burnout. Training is a promising approach to improving age-differentiated leadership and recovery in organizations and, consequently, health and performance. In addition, the dissertation extended findings of age-differentiated leadership towards additional sectors (e.g., car manufacturing), perspectives (individual, team, and supervisor) SMEs, and associations with recovery and absenteeism. It also showed that training could deliver age-differentiated leadership and recovery. Furthermore, the dissertation fulfilled Bell et al. (2017)`s request for further comparison between web-based and face-to-face training programs, while also incorporating the web-based attendance (adherence perspective). With respect to the JD-R model underlying the tested hypotheses in the three studies it can be concluded that both age-differentiated leadership and recovery can be integrated into this framework. Moreover, an association between these two added components was confirmed. Future research should investigate this interaction in more detail. In addition, training is an approach to improving these components.

Die Dissertation befasst sich am Beispiel Berlins mit den Wechselwirkungen zwischen der Alterung der Gesellschaft und wachsender Diversität. In sechs Fachartikeln werden methodologische Zugänge zum Zusammenspiel von Alter und Diversität entwickelt und neue empirische Befunde aus qualitativer und quantitativer Empirie vorgestellt. Auf Basis der empirischen Erhebungen wird gezeigt, inwiefern gängige gesellschaftliche Altersbilder den komplexen Lebenslagen im Alter nicht gerecht werden, und entsprechend auch der institutionelle Umgang mit Diversität im Alter vielfach nicht adäquat ist. Daran anknüpfend schlägt die Arbeit eine räumliche Perspektive als methodologischen Zugang für die Analyse des Zusammenspiels von Alter und Diversität vor. Aus dieser räumlichen Perspektive werden drei empirische Beispiele analysiert: Die Nutzung öffentlicher Parks durch ältere Menschen, Umzugspläne und Umzugsmotivationen im Alter, sowie die Bedeutung der räumlichen Nähe für das Entstehen von sozialen Netzwerken in der Nachbarschaft im Alter. Die Arbeit leistet damit sowohl auf empirischer als auch auf analytischer und methodologischer Ebene einen wissenschaftlichen Beitrag: Sie vermittelt zunächst vertiefte Einblicke in die Lebenslagen älterer Menschen mit unterschiedlichen Hintergründen. Auf dieser Basis hinterfragt die Arbeit die implizite Normierung der mittleren Lebensjahre als objektiven Beobachterhorizont und unterstreicht die Notwendigkeit, Diversität mehrdimensional zu denken. Die Arbeit plädiert insofern dafür, die Konzepte Intersektionalität und Superdiversität zu verknüpfen, um auch innerhalb sozialer Gruppen genauer differenzieren zu können. Dabei erlaubt eine räumliche Perspektive einen offenen Blick auf Diversität und ermöglicht es, die bislang getrennten Forschungsfelder der Diversitäts- und Altersforschung zu verbinden. Die Arbeit schließt mit Handlungsempfehlungen für Politik und Planung. / The dissertation deals with the interplay between the aging of society and growing social diversity, drawing on Berlin as a case study. In six papers, the dissertation develops methodological approaches to scrutinize the interplay of age(ing) and diversity and presents new empirical findings from qualitative and quantitative empirical research. Based on the empirical findings, the dissertation shows that prevalent societal images of old age do not do justice to the complex life situations of older people and, accordingly, the institutional handling of older people’s diversity is inadequate. In addition, the thesis develops a spatial perspective as methodological approach to analyze the interplay between age(ing) and diversity. Employing this spatial perspective, the thesis examines three empirical cases: The use of public parks by older people, relocation plans of older people, and the importance of spatial proximity for older people’s social networks in the neighborhood. The dissertation thus makes a scientific contribution on an empirical as well as on an analytical and methodological level: First, it provides in-depth insights into the life situations of older people with different backgrounds. On this basis, the thesis questions the implicit norming of middle age as an objective perspective and underlines the necessity of thinking diversity in a multidimensional way. In this respect, the paper argues for linking the concepts of intersectionality and superdiversity in order to differentiate more precisely within social groups. A spatial perspective allows an open view on diversity and makes it possible to connect the previously separate fields of research on diversity and gerontology. The work concludes with recommendations for policy and planning

Ein gesundes Alter(n) ist sowohl auf individueller Ebene als auch auf gesellschaftlicher Ebene von großer Relevanz. So wächst die Bedeutung von Prävention und Gesundheitsförderung bis ins hohe Alter – einerseits, um die Autonomie, Selbstbestimmtheit, soziale Teilhabe und Lebensqualität des älteren Menschen aufrecht zu erhalten und andererseits, um den durch den demografischen Wandel bedingten gesundheitspolitischen Herausforderungen begegnen zu können. Dabei weist der gesundheitliche Status im Alter neben hoher Vulnerabilität eine Vielzahl an Ressourcen und somit Ansatzpunkte für präventive und gesundheitsförderliche Interventionen auf. Technische Innovationen bieten hier ein wachsendes Potenzial, um Maßnahmen dieser Art zu stützen. Zur Erschließung des neuartigen Themenfeldes werden die Ergebnisse dreier Einzeluntersuchungen berichtet, in welchen sowohl qualitative als auch quantitative Methoden angewandt werden. Mit Hilfe der Durchführung von Expertinneninterviews werden Bedarf und Potenzial innovativer Technik in Prävention und Gesundheitsförderung für Ältere und erste Anforderungen an eine solche Technik erfasst. Eine innovative Möglichkeit zur Umsetzung präventiver und gesundheitsförderlicher Interventionen bieten digitale Bewegungsspiele. So werden darauffolgend im Rahmen einer quasi-experimentellen Kohortenstudie gesundheitsbezogene Veränderungen durch das Spielen sog. Serious Games im Setting (teil-)stationäres Pflegewohnen evaluiert. Die Ergebnisse zeigen erste gesundheitsförderliche Tendenzen. Innerhalb einer Fokusgruppe werden abschließend drei digitale Bewegungsspielsysteme unter Beachtung zielgruppenspezifischer Bedarfe bewertet und notwendige Ressourcen für den erfolgreichen Einsatz im Anwendungskontext erarbeitet. Um die neugewonnenen Erkenntnisse in nachhaltiger Form nutzbar zu machen, werden diese in einem Anforderungskatalog für die erfolgreiche Implementierung eines digitalen Bewegungsspiels im Kontext der Pflege zusammengefasst. / Being healthy in old age and aging healthily is of great relevance at both the individual and societal level. Thus, the importance of prevention and health promotion even in an old age is growing - on the one hand, to maintain the autonomy, self-determination, social participation and quality of life of the elderly and, on the other hand, to be able to meet the health policy challenges caused by demographic change. Health in old age is not only highly vulnerable but also offers a multitude of resources and starting points for preventive and health-promoting interventions. Technical innovations offer a growing potential to support measures of this kind. In order to open up this new field of research, the results of three individual studies are reported, in which both qualitative and quantitative methods are applied. By conducting expert interviews, the need and potential of innovative technology in prevention and health promotion for the elderly as well as first requirements for such a technology are identified. Digital exercise games offer an innovative possibility for the implementation of preventive and health-promoting interventions. Subsequently, health-related changes caused by playing digital exercise games, so-called serious games, in the setting of nursing care are evaluated within the framework of a quasi-experimental cohort study. The results show first health-promoting tendencies through playing serious games. Last, three digital exercise game systems will be evaluated in a focus group on the basis of the needs of the target group. Additionally, the necessary resources for successful use of such systems in a real application context are developed in a participatory way. In order to make the newly gained knowledge usable in a way that is sustainable and relevant for practical use, it is then summarized in a catalogue of requirements for the successful implementation of a digital exercise game in the nursing environment.