Work ability
In the 1980s, the concept of work ability was developed by the Finnish Institute of Occupational Health. This concept represents employees’ ability to fulfill their job demands according to their human resources (Ilmarinen
1999). Fundamental to work ability is a person’s health, including physical, mental, and social capacities. Other necessary human resources are education and competence, values, attitudes, and motivation. A person’s work ability is high if these resources are in balance with working conditions (Ilmarinen
2001). Work ability may serve as an indicator of the likelihood of early retirement or extended periods of sick leave. According to data from the German lidA Cohort Study on Work, Age and Health, which included 3,796 participants 46 years of age or older, self-perceived work ability had a direct effect on participants’ decision to end their employment (Tisch
2015).
Work ability is a dynamic concept: On the one hand, human resources change, particularly as an employee ages, and physical and mental capacities decline (van den Berg et al.
2008). On the other hand, work and working conditions (e.g., new technology) are in flux, which can challenge aging employees (Ilmarinen
2001). Therefore, work ability depends strongly on the work environment: According to a systematic review of working conditions and the Work Ability Index, high mental and physical demands and low control were associated with poor work ability (van den Berg et al.
2008). The employee’s perception of management’s leadership quality is another component of working conditions that might affect work ability: Cross-sectional and longitudinal studies have shown a negative association between poor management and work ability (Tuomi et al.
2001,
1997). Another German study focused on the relationship among working conditions, work ability and depressive symptoms: In this study, decreasing demands and increasing leadership quality between the two waves were associated with higher work ability, while the effects regarding job control and social support were positive but rather small (Weber et al.
2021).
Job demands–control model
Karasek’s (
1979) JDC model is a widely applied and tested theoretical foundation for explaining the occurrence of strain due to working conditions (e.g., Rijk et al.
1998; van Yperen and Hagedoorn
2003). The JDC model characterizes work as having two components: job demands and control on the part of the employee. Job demands are understood to include such factors as quantitative workload and conflicting demands, while control comprises decision authority and autonomy over tasks. According to the JDC model, physiological strain results from a combination of high work demands and limited decision latitude and describes a highly stressful job (the job strain hypothesis). If high job demands can be compensated with more decision latitude, employees are able to organize the way their work is executed and can channel their energy into useful activities that allow them to release strain (the buffering or learning hypothesis). Karasek (
1979) originally developed the model to predict physiological strain, but it has since been broadened to address effects on mental factors, such as burnout (Rijk et al.
1998), depression (Blackmore et al.
2007), or even mortality (Gonzalez-Mulé and Cockburn
2021), enabling an employee’s overall health status to be explained by the model.
Since health is considered a key determinant of work ability (Ilmarinen
2001), it can be assumed that work ability can also be explained using the JDC model. High demands reduce work ability, while control over tasks has a positive impact on work ability. In a Swedish study involving 7,810 respondents, male employees with low skill discretion—a component of control—had a lower work ability over the 7-year follow-up study (Leijon et al.
2017).
As far as the interplay between the different components of the JDC model is concerned, a meta-analytic review of 106 studies concluded that these interrelationships need to be further examined both theoretically and empirically. The originally proposed interaction between job demands and control often showed no significant effects on different outcomes (Luchman and González-Morales
2013). Overall, the state of research is equivocal (de Lange et al.
2003; Meier et al.
2008): Taris (
2006) found that only 10% of the 63 studies of the JDC model reviewed by van der Doef and Maes (
1998) supported the moderation of demand and control. Consequently, there is still a great need to test this model, which leads to our first three hypotheses:
Hypothesis 1 (H1): Job demands have a negative effect on work ability.
Hypothesis 2 (H2): Job control has a positive effect on work ability.
Hypothesis 3 (H3): Job control moderates the negative relationship between job demands and work ability, such that the influence will be weaker when job control increase.
Demanding leadership behavior—the role of destructive leadership
The JDCS model proposed by Johnson et al. (
1989) already included support but did not distinguish the sources of support (co-workers or leaders), thus preventing a more detailed look at the possible effects of leaders per se. Nevertheless, leaders play a central role when one is examining the effects of working conditions on employees' ability to work, because leadership behavior influences their perception of work (Fernet et al.
2015; Sparrowe and Liden
1997) and can actively shape working characteristics (Schaufeli
2015).
In practice, it becomes apparent that not only a lack of supportive leadership behavior (Aasland et al.
2010), but even hostile leadership behavior is often prevalent (Tepper et al.
2017). Thus, over the last decade, destructive leadership behavior has increasingly become the focus of leadership research owing to its negative impact on organizational outcomes (Mackey et al.
2021; Schyns and Schilling
2013). Destructive leadership has been found to have detrimental effects on such outcomes as job satisfaction, well-being and stress among employees (Schyns and Schilling
2013). In the long run, Schmidt et al. (
2018) found that when such supportive leadership behaviors were lacking, employees' self-assessed health over a 10-year period was significantly poorer compared with that of employees who felt supported. In our study, destructive leadership is understood to include both actively negative leadership behavior such as abusive supervision (Tepper
2000), in keeping (partially) with the definitions of e.g., Shaw et al. (
2011) and Skogstad et al. (
2007).
In contrast to the transformational leader, who demonstrates to employees the importance of their work (Yukl
2010), thus improving their performance by increasing their self-worth and intrinsic motivation (Bass
1985), the destructive leader exhibits neglectful behavior by being absent or even displays hostile behavior through verbal abuse or unwarranted punishment, thus impairing employees’ performance and well-being (Tepper et al.
2017). According to Zwingmann et al. (
2014), the health-promoting, stress-reducing effects of transformational leadership in particular could be attributed to this concept’s core characteristics, which include support, empowerment and a high-quality relationship between leaders and their employees. In addition, transformational leadership has a resource-saving function through its influence on employees’ self-concept (Shamir et al.
1993), which helps them cope with work demands. Related to the concept of destructive leadership and based on the JDCS model, such a stress-reducing effect is absent when no support is given and the relationship between leader and employees is of low quality (Buch et al.
2015). Considering destructive leadership, one can assume that destructive leaders strain the resources of their followers, considerably impairing employees' ability to work and exacerbating the effect of high job demands on work ability. This assumption is supported by a Dutch study involving 19,507 construction workers in which low levels of supervisor and co-worker support had negative effects on work ability (Alavinia et al.
2007). Similar results were reported in a study involving Australian health care workers (McGonagle et al.
2014).
Hypothesis 4 (H4): Destructive leadership has a negative effect on work ability.
Within the framework of the JDCS model (Johnson et al.
1989), leadership can be seen as the supportive component and is described as a factor that can mitigate tension due to less favorable working conditions, such as high job demands and low levels of control (Westerlund et al.
2010). Accordingly, leadership can be seen as a moderating influence in the relation between job demands and employees’ well-being. However, destructive leaders can negatively affect an employee’s self-concept (Vogel and Bolino
2020), potentially resulting in a loss of resources and greater difficulty in dealing with high work demands. In their recent systematic review of the leadership research, Tummers and Bakker (
2021) point out that, only a few studies have examined the moderation of demands and leadership and that the results regarding such moderation were not consistent. Consequently, there is still a large research gap when it comes to the impact of leadership and its interplay with job demands with respect to work ability. To help address this gap, we investigated the following hypothesis:
Hypothesis 5 (H5): Destructive leadership moderates the negative relationship between job demands and work ability, such that the influence will be stronger for employees with a destructive leader.