We know of three studies that examined genetically mediated child effects on maltreatment. A study of female twins from the Virginia Twin Registry estimated that genetically mediated child effects accounted for 9–21% of parent-reported and 33–40% of child-reported physical discipline (Wade and Kendler 2000). A twin study of parent-reported corporal punishment and physical maltreatment sufficient to injure the child estimated that genetically mediated child effects accounted for 25% of the variance in corporal punishment and 0–7% of the variance in physical maltreatment (Jaffee et al. 2004a, b). A study of retrospectively reported childhood maltreatment in the same sample examined in the present study indicated that approximately 1–6% of the variance in a composite maltreatment variable, 3–28% of variance in physical maltreatment, 3–32% of variance in neglect, and none of the variance in sexual maltreatment is due to genetically mediated child effects (Schulz-Heik et al. 2009).
