Hierarchical organization of personality and prediction of behavior

Two studies evaluated personality trait measures and Big Five factor measures for their accuracy in predicting important behavior criteria. The results of both studies showed that the narrower traits and the broader factors, thought to define 2 levels of a hierarchy of personality variables, separately predicted most criterion variables. However, the incremental validity of the personality trait measures (the degree to which the traits increased the criterion prediction achieved by the factors) was generally much larger than the incremental validity of the Big Five factor measures. It was concluded that aggregating personality traits into their underlying personality factors could result in decreased predictive accuracy due to the loss of trait-specific but criterion-valid variance.