The authors examined the validity of observer ratings (supervisor, coworker, and customer) and selfratings of personality measures. Results based on a sample of 105 sales representatives supported the 2 hypotheses tested. First, supervisor, coworker, and customer ratings of the 2-job-relevant personality dimensions - conscientiousness and extraversion - were valid predictors of performance ratings, and the magnitude of the validities were at least as large as for self-ratings. Second, supervisor, coworker, and customer ratings accounted for the significant variance in the criterion measure beyond self-ratings alone for the relevant dimensions. Overall, the results suggest that validities of personality measures measures based on self-assessments alone may underestimate the true validity of personality constructs.
Abstract