conduct disorder symptomatology was elevated (21%). It is possible that within the latter group—which comprised more densely affected families—either the high prevalence of child maltreatment reports (much higher than that observed in any of the twin groupings) or the nature of inherited risk within a sample ascertained on the basis of alcohol dependence, minimizes the relevance of non-report in a way that distinguishes substantiated reports as specific predictors of antisocial outcome. The data for less densely affected families in the COGA sample is more difficult to interpret because of sample size limitations.
