Although there is some evidence in support of convergence between the TCI and FFM, they differ in how the underlying models were created, with the FFM based on a lexical analysis of trait adjectives and the TCI based on a theoretical model that sought to account for individual differences in personality by integrating neurobiological systems, learning and social influences (for a review, see Stallings et al.5). In a sample of 130 individuals that had been administered both the TCI and the NEO-PI-R (representing the FFM2), De Fruyt6 used a multiple regression approach to show that 23–51% of the variance in the TCI scales was explained by the NEO-PI-R scales, and 29–55% of the variance in the NEO-PI-R scales were explained by the TCI scales, indicating a substantial portion of the variance in each of the TCI and NEO-PI-R unaccounted for by the other.
