The Counterpoint of Personality Assessment: Self-Reports and Observer Ratings.

In musical counterpoint, two or more different voices sound together in ways that illuminate the possibilities of the musical theme. Similarly, self-reports and observer ratings together may tell us more about personality than either could separately. This article reviews convergence between these two data sources and illustrates ways in which they can be used jointly in personality research to rule out response biases and estimate stability and heritability of personality traits. A measure of profile agreement is introduced and a rule of thumb is proposed for distinguishing agreement from disagreement on specific traits in individual cases. Averaging may be useful when there is agreement about individuals across observers; when there is disagreement, further information should be sought to resolve the competing hypotheses offered by the discrepant ratings.