Within-Individual Age-Related Trends, Cycles, and Event-Driven Changes in Job Performance: a Career-Span Perspective

Past research on age-related differences in job performance have focused primarily between-person comparisons. In the present study, we examine within-individual changes in supervisor-rated job performance to examine the influence of age-related trends, cycles, and event-driven factors. Our analysis is based on an eight-wave dataset from a multiple-cohort sample of employees (N = 750) varying in age from 25 to 65 years. We used an age-sequential design to disentangle maturation effects from historical effects. Results showed that population-level, within-individual change in a general measure of job performance was characterized by an increase in the first phase of the career (workers of 25-30 years), and then by a progressive decline. Within-individual levels of job performance were generally higher for younger workers than for older workers, and mostly reflected the influence of population-level trends but some even-driven effects as well. Results were in line with predictions from Baltes and Baltes's (1990) meta-theory of selective optimization with compensation and the effects of age-related losses on performance. Results also provide insights into understanding the job performance trajectory over the career span.