Should We Focus More on Individual Differences or on Job Attitudes for Increased Job Performance? Four Decades of Research and a Monte Carlo Simulation

This study examines how stable individual differences and malleable job attitudes differentially translate into job performance, with a focus on quantifying relative efficiency contrasts under equalized assumptions. On one hand, we consider performance gains that follow from increasing levels of stable individual differences; on the other, we consider illustrative utility implications derived from job attitude associations. Based on an input matrix extracted from meta-analyses we conduct a Monte Carlo simulation for three alternative models linking individual differences and job attitudes to task and contextual job performance. We hereby untangle unique and shared validities while avoiding a substitutive “either/or” framing, and clarify where marginal performance leverage tends to reside per standardized unit increase in each class of predictors.