Additionally, a plot of the observed correlation in DZos against its expected value based on the DZss (male-male and female-female) correlations is shown in Figure 6. This figure reflects the similarities and differences between the correlations in same-sex twin pairs and opposite-sex twin pairs. There are few traits for which the resemblance of opposite-sex pairs deviates from the expectation based on the same-sex correlations. For Lifestyle, all correlations in adult DZos twins equaled those in DZss twins. In adolescents, sex-differences were observed for Ever Use of Alcohol and Weekly Alcohol Use (see Figure 1A and 1B). Additional tests for these traits suggest that twins from DZos pairs shared fewer environmental factors than twins from same-sex DZ pairs (φ respectively 0.79 and 0.66), see Table S7B. For Emotional and Behavioral Problems significantly lower correlations were found in adult DZos twins for Thrill and Adventure Seeking and Sensation Seeking (Figure 2A and 2B). The subsequent model fitting analyses for these traits (Table S7A, B, C) suggested that different genes are expressed in adult men and women (γ in DOS pairs of respectively
