In order to maximize reliability, a composite of physical maltreatment, neglect, and sexual maltreatment was examined, as diverse types of maltreatment tend to co-occur (Dong et al. 2004). Phenotypic correlations among the three forms of maltreatment ranged from 0.36 to 0.48, all of which were statistically significant at the p < 0.05 level. These correlations were consistent across male, female, and opposite sex pairs, with no correlation differing by more than 0.08 across these groups. The composite maltreatment variable was computed by first assigning a z-score that corresponded to each participant’s location in the distribution for each form of maltreatment. z-Scores were averaged across forms of maltreatment, and then this variable was transformed into an ordinal variable with five levels. This composite variable and each of the three individual forms of maltreatment was previously subjected to univariate behavior genetics decomposition (Schulz-Heik et al. 2009). Neglect was the most frequently endorsed form of maltreatment (41% endorsed at least one experience), followed by physical maltreatment (29%) and sexual maltreatment (5%).
