Second, we conducted a joint EFA on the lower-order scales of all the inventories and evaluated the matrix of factor correlations emerging from oblique rotations. This approach is similar to the strategy used by Markon, Kreuger, and Watson (2005) to evaluate the hierarchy of personality constructs. However, our explicit focus was on the magnitude of the factor inter-correlations that emerge from a joint analysis of multiple personality inventories whereas Markon et al. (2005) used orthogonal rotations so that the factor inter-correlations were fixed to zero. We used EFA rather than CFA for these analyses to limit the likelihood that correlations among higher-order factors would be artificially high because of unspecified cross-loadings.
