single common additive genetic, shared environmental, and nonshared environmental components along with criterion-specific additive genetic, shared environmental, and nonshared environmental effects. Models omitting the common and criterion-specific C components, and then including additional A and E common components, were tested next. Criterion-specific nonshared environmental effects were not set to zero in any of the models tested because this entails the unrealistic assumption that individual responses to items were reported without error. Final orthogonal factor loadings were obtained using a varimax rotation.
