Joint factors in self-reports and ratings: Neuroticism, extraversion and openness to experience

Although most dimensional theories of personality assume that the same traits can be assessed in either ratings or self-reports, joint factor analyses of data from these two methods have seldom provided clear evidence in support of this position. Previous analyses have found a preponderance of within-method factors, or have had to transform variables or use unorthodox rotational procedures in order to control the effects of method variance. The present study argues that recent conceptual and technical advances should now make it possible to show joint factors at the second-order level using standard factor techniques. The NEO Inventory and NEO Rating Form, which measure 18 traits in the domains of Neuroticism, Extraversion and Openness to Experience, were administered to a sample of 281 men and women. Varimax rotation of three principal components clearly showed the hypothesized structure within and across self-reports and spouse ratings. Convergent and discriminant validity of the joint factors with the EPI scales was also shown. The results suggest that the effects of method variance can be minimized if well-qualified raters use psychometrically adequate instruments to provide ratings of clearly conceptualized traits. In addition, they provide strong evidence for the validity of the proposed three-domain model of personality.