Several limitations of the present study should be considered when interpreting the results. First, the assessment of maltreatment was not ideal. Neglect was assessed via only two items and physical and sexual maltreatment were assessed via only one item each. Each item was assessed on an ordinal scale. Also, maltreatment experiences that occurred prior to the age of 12 were assessed retrospectively at an average age of 21. Thus, results may not only reflect influences on maltreatment but also on its retrospective recall. Therefore, the large estimates of the nonshared environment may actually reflect large measurement error. However, research suggests that retrospective reports affirming the occurrence of child sexual maltreatment (Williams, 1992), physical maltreatment (Berger et al., 1988), and other adverse childhood events (Brewin et al. 1993) are typically valid. Also, Kendler and Baker’s (2006) review of the heritability of parenting and other ‘environmental’ variables suggested that self-report and informant-report yielded similar heritability estimates and that observer-reports yielded lower estimates. They argued that this is likely due to unreliability of observer reports, which were based on ten minutes or less
