We present path estimates and 95 % CIs for the best-fitting model 1 in Fig. 1a (males) and Fig. 1b (females), variance components with 95 % CIs in Table 6, and the decomposed genetic and environmental influences on the three disorders in both males and females in Table 7. Six results are noteworthy. First, the latent construct of externalizing disorders was highly heritable in males (a2 = 0.62) and especially in females (a2 = 0.76). Second, shared environmental influences on the latent trait of externalizing disorders was considerably stronger in males (c2 = 0.23) than in females (c2 = 0.03). Third, in both sexes, loadings on the externalizing disorder common factor were strongest for DA and weakest for CB. This difference was substantially greater in females than males. Fourth, for all three externalizing syndromes in males, and DA and AUD in females, the large majority (75–92 %) of genetic risk factors were shared with the other externalizing disorders (Table 7). The exception was CB in females where over half of the total heritability derived from syndrome-specific genetic risk factors. Fifth,
