These analyses, conducted in a large general population twin sample, had three major aims. The first was to determine whether the broad structure of the disorders and the traits that index the genetic common factors underlying the externalizing and inzing spectra were the same in males and females. The second aim was to characterize in detail the pattern of disorders and traits, and their loadings on these two genetic common factors. The third was to determine, once we knew how to index them, the correlation between the genetic common factors for the externalizing and the internalizing spectra. We review these results in turn.
