A century of research on conscientiousness at work.

Evidence from more than 100 y of research indicates that conscientiousness (C) is the most potent noncognitive construct for occupational performance. However, questions remain about the magnitudes of its effect sizes across occupational variables, its defining characteristics and functions in occupational settings, and potential moderators of its performance relation. Drawing on 92 unique meta-analyses reporting effects for 175 distinct variables, which represent > 1.1 million participants across > 2,500 studies, we present the most comprehensive, quantitative review and synthesis of the occupational effects of C available in the literature. Results show C has effects in a desirable direction for 98% of variables and a grand mean of [Formula: see text] (SD = 0.13), indicative of a potent, pervasive influence across occupational variables. Using the top 33% of effect sizes [Formula: see text] we synthesize 10 characteristic themes of C's occupational functioning: 1) motivation for goal-directed performance, 2) preference for more predictable environments, 3) interpersonal responsibility for shared goals, 4) commitment, 5) perseverance, 6) self-regulatory restraint to avoid counterproductivity, and 7) proficient performance-especially for 8) conventional goals, 9) requiring persistence. Finally, we examine C's relation to performance across 8 occupations. Results indicate that occupational complexity moderates this relation. That is, 10) high occupational complexity versus low-to-moderate occupational complexity attenuates the performance effect of C. Altogether, results suggest that goal-directed performance is fundamental to C and that motivational engagement, behavioral restraint, and environmental predictability influence its optimal occupational expression. We conclude by discussing applied and policy implications of our findings.