Exploring how constraints created by other people influence intraindividual variation in objective performance measures.

Objective performance indicators have low test-retest reliability, particularly in complex jobs. Yet, little is actually known about the reasons why objective performance indicators lack temporal stability. The authors address this issue by using data from a sample of 106 professional football players to explore how the actions of other people influence intraindividual variation in performance. Results suggest that weekly measures of performance outcome exhibit substantial variability within individuals. A significant portion of this within-person variance is explained by environmental fluctuation created by the constraining actions of other people. Individuals with highly fluctuating past performance exhibit stronger relationships between the actions of competitors and subsequent performance outcomes. The intraindividual relationship between fluctuating constraints and performance outcomes is also stronger for individuals in more complex jobs.