Career plateau has been identified as stressful experiences that can lead to employee negative feelings and attitudes in the workplace. However, empirical studies that examine how career plateau relates to employee outcomes and the conditions that moderate the above relationships have been scarce. Using an occupational stress model as the foundation, this study examined whether two types of career plateau (i.e., hierarchical plateau and job content plateau) relate to employee outcomes (emotional exhaustion, job satisfaction, and affective organizational commitment). Furthermore, this study examined whether the proposed psychological processes (future career uncertainty and subjective monotony) mediate the above relationships and whether components of workplace spirituality (i.e., inner life and belongingness to community) moderate the relationship between career plateau and psychological processes. Based on responses of 243 participants, hierarchical regression results indicate that both plateaus relate negatively with job satisfaction, job involvement, and affective organizational commitment. However, only hierarchical plateau relates positively to emotional exhaustion, whereas job content plateau is not related to emotional exhaustion. Also, individuals’ future career uncertainty partially mediates the relationship between hierarchical plateau and employee emotional exhaustion and job attitudes, whereas subjective monotony partially mediates the relationship between job content plateau and job attitudes, but completely mediates the relationship between job content plateau and emotional exhaustion. Furthermore, only the inner life component of workplace spirituality moderates the relationship between hierarchical plateau and future career uncertainty. Based on the study findings, managerial implications, limitations and suggestions for future research directions are given.

The changing working environment and ageing workforce suggest that many workers will inevitably reach a career plateau, a stage where people regard future promotions as unlikely, or no longer feel challenged at work. Experiencing career plateau is found to be associated with negative job attitudes and performance in the workplace. However, existing studies have been mainly cross-sectional in design and few of them investigate the mechanisms and the conditions that influence the negative relationship. This study follows a quantitative longitudinal research design to further enhance the understanding of the relationships between career plateau and job outcomes. The job outcomes in this research include work attitudes such as job satisfaction, organisational commitment, turnover intentions and three aspects of job performance. Specifically, the three research aims of this thesis are: (1) to understand the causal directions between career plateau and job outcomes, (2) to examine whether employees’ unmet expectations may explain these relations and (3) to investigate whether employees’ age may modify the mediation effects of career plateau on job outcomes via unmet expectations. Three waves of data were collected from working individuals in various industries over an eight-month period. The majority of the participants were working in the UK or in Taiwan. Results showed that unmet expectations partially explain the negative relationship between career plateau and job attitudes over time but not for job performance. Furthermore, age did not affect the strength of the mediation effect of career plateau on the job outcomes through unmet expectations. The significance of this research is three-fold. First, it provides a new explanation for the unfavourable work attitudes of plateaued individuals. The findings that career plateaued employees have lower job satisfaction, lower organisational commitment and higher turnover intentions can partly be explained by unfulfilled expectations in receiving promotions or challenging tasks. Second, the study signals the danger of career plateau at any age, as younger and older workers were found to be equally influenced by career plateau. Finally, this is the first study in the area that seeks to resolve the debate over the directional relationship between career plateau and job outcomes. The implications in theory and in practice, limitations and suggestions for future research directions are discussed.