Curvilinear relationships between age and job performance and the role of job complexity

Despite suggestions that work performance varies with age, the empirical evidence is inconclusive and contradictory. Possible reasons for this are the lack of differentiation between different types of performance and a naive assumption of a negative linear relationship between age and task performance across the working lifespan. With this study we question and revisit these expectations. We take a lifespan perspective to explore differential and curvilinear relationships between age (measured as chronological age) and three types of task performance (task proficiency, proactivity, and adaptivity), moderated by job complexity (measured as cognitive demands). Using Bayesian polynomial regression on survey data from 903 employees, we tested the relationships between age and each performance type, with job complexity as a moderator. The data indicated a U-shaped age-adaptivity relationship (main effects for job complexity) and an S-shaped age-proactivity relationship that was more pronounced under low job complexity (interaction effect). We identify the turning points for these changes, which show midlife as a critical period for changes in performance where the job context itself shapes the gradient and direction of these changes. Our findings provide crucial evidence that different types of job performance vary by age and the role of perceived job complexity in explaining trajectories in proactivity and adaptivity. Implications for job design, organizational interventions, and human resource management are discussed.