Cross-rater agreement on common and specific variance of personality scales and items

• Self–other agreement on the unique variance of facet scales was substantial.
• Self–other agreement on the unique variance of single items was substantial.
• Facets and single items capture consensually valid and possibly useful variance.

Using the NEO Personality Inventory-3, we analyzed self/informant agreement on personality traits at three levels that were made statistically independent from each other: domains, facets, and individual items. Cross-rater correlations for the common variance in the five domains ranged from 0.36 to 0.65 (M = 0.49), whereas estimates for the specific variance of the 30 facets ranged from 0.40 to 0.73 (M = 0.56). Cross-rater correlations of residual variance of individual items ranged from −0.14 to 0.49 (M = 0.15; 88% statistically significant at p < 0.002). Agreement on common variance was moderately related to item observability and evaluativeness, whereas variance played a larger role. Facets and even single items detect nuances of personality variation that may merit substantive attention.