Unfinished Tasks Foster Rumination and Impair Sleeping – Particularly if Leaders Have High Performance Expectations Christine J. Syrek and Conny H. Antoni University of Trier This study examines the relationship between time pressure and unfinished tasks as work stressors on employee well-being. Relatively little is known about the effect of unfinished tasks on well-being. Specifically, excluding the impact of time pressure, we examined whether the feeling of not having finished the week’s tasks fosters perseverative cognitions and impairs sleep. Additionally, we proposed that leader performance expectations moderate these relationships. In more detail, we expected the detrimental effect of unfinished tasks on both rumination and sleep would be enhanced if leader expectations were perceived to be high. In total, 89 employees filled out online diary surveys both before and after the weekend over a 5-week period. Multilevel growth modeling revealed that time pressure and unfinished tasks impacted rumination and sleep on the weekend. Further, our results supported our hypothesis that unfinished tasks explain unique variance in the dependent variables above and beyond the influence of time pressure. Moreover, we found the relationship between unfinished tasks and both rumination and sleep was moderated by leader performance expectations. Our results emphasize the importance of unfinished tasks as a stressor and highlight that leadership, specifically in the form of performance expectations, contributes significantly to the strength of this relationship. Keywords: leadership, performance expectations, sleep, unfinished tasks, work-related rumination That work stressors impair sleep and foster rumination seems plausible, and empirical evidence supports this relationship (Ber- set, Elfering, Lüthy, Lüthi, & Semmer, 2011). In this study, we attempt to extend the previous research by confirming this asso- ciation for the stressor unfinished tasks and by investigating a potential moderator variable in a diary study design. Specifically, we expect that the relationships between unfinished tasks and both rumination and sleep are moderated by leader performance expec- tations. Although the growth of the information and service sectors and the raise of new technologies have reduced physical strain (Mohr, Müller, Rigotti, Aycan, & Tschan, 2006), the challenges of bal- ancing work with life and of coping with increasing work demands have led to an immense increase of mental strain for employees (Mohr et al., 2006; Statistisches Bundesamt, 2013). It is well-documented that work stressors impair employee health and well-being (Bakker & Demerouti, 2007). The two most influential models with regard to stress in relation to health and well-being are the effort-recovery model (Meijman & Mulder, 1998) and conservation of resources model (Hobfoll, 1998). Both models emphasize the crucial need for recovery. Recovery refers to the process of restoring resources when the person is no longer exposed to the demands of work (Sonnentag & Fritz, 2007). Insufficient recovery can be viewed as the mechanism linking stress to chronic health impairment (Geurts & Sonnentag, 2006). Cropley and Zijlstra (2011) argue, “thinking of work is one of the main determinants for (absence of or delayed) recovery” (p. 487). Rumination can be described as conscious and recurrent thoughts about work-related aspects in the absence of demands necessitating these thoughts (Martin & Tesser, 1996). A substan- tial number of studies provide evidence that rumination is associ- ated with indicators of psychological disorders (e.g., depression and anxiety; Muris, Roelofs, Rassin, Franken, & Mayer, 2005), and fatigue (Querstret & Cropley, 2012). A laboratory study by Roger and Jamieson (1988) reports that engaging in perseverative thoughts is associated with prolonged physiological arousal and delayed recovery. Thus, detaching from work after an intense working day is central to preventing further health impairment. Sleep is regarded as crucial for recovery and essential for health and well-being (National Sleep Foundation, 2013). Moreover, sleep is associated with feeling a purpose in life (Steptoe, O’Donnell, Marmot, & Wardle, 2008). An emerging body of evidence shows the consequences of impaired sleep. For example, sleep quality and quantity are clearly linked to the risk for devel- oping Type 2 diabetes (Cappuccio, D’Elia, Strazzullo, & Miller, 2010). Impaired sleep is also recognized to be strongly related to depression and anxiety (Jansson-Fröjmark & Lindblom, 2008) and mortality (Heslop, Smith, Metcalfe, Macleod, & Hart, 2002). In a diary study, Scott and Judge (2006) revealed that insomnia in- creased hostility and fatigue and decreased joviality, attentiveness, and job satisfaction. This article was published Online First June 16, 2014. Christine J. Syrek and Conny H. Antoni, Department of Work and Organizational Psychology, University of Trier. This study was part of a network project “Allwiss - Working, Learning, Living in the Field of Knowledge Work” funded by a grant from the German Ministry of Education and Research and the European Social Fund (Grant ID: ADFH01241608). Correspondence concerning this article should be addressed to Christine J. Syrek, Department of Work and Organizational Psychology, University of Trier, D-54286 Trier, Germany. E-mail: syrek@uni-trier.de This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. Journal of Occupational Health Psychology © 2014 American Psychological Association 2014, Vol. 19, No. 4, 490 – 499 1076-8998/14/$12.00 http://dx.doi.org/10.1037/a0037127 490