An examination of the cross-sibling within-trait correlations in Table 2 sheds light on this pattern of results. In males, the MZ correlation is substantially higher than the DZ correlation (.33 vs. .03), but the MZ and full sibling correlations are the same (.33 and .33). Therefore, this result indicates a lack of genetic influences on physical maltreatment in males. In females, the MZ and DZ correlations are very similar (.55 and .56), and are higher than the full sibling correlation (.30), also indicating a lack of genetic influences on physical maltreatment. However, if data from males and females are combined, the overall MZ correlation is higher than the DZ and full sibling correlations (.46 for MZs, .32 for DZs, and .30 for full siblings). Therefore, the conclusions from the homogeneity and heterogeneity models are conflicting.
