Table 2 provides a complementary perspective on the results of this best-fit model. This Table depicts estimated percentages of overall variance in liability to each of the CD criteria attributable to the aforementioned genetic, shared environmental, and nonshared environ mental influences and decomposes variance associated with each into portions reflecting common factors and criterion-specific influences. Focusing first on variance in individual symptoms attributable to genetic vs environmental influences: (1) In general, nonshared environmental influences account for the greatest proportion of variance in CD symptoms (>45% in all cases), followed by genetic influences (> 15% in all but 2 cases), with shared environment accounting for the least (>5% in only 5 cases). (2) The relative contribution of genes to overall variance is highest for the 2 criteria that most strongly define the rule-breaking factor (running away and hooky) and the 2 that most strongly define the overt aggression factor (fights and hurting people). (3) The 5 criteria for which the contribution of shared environment is highest (10%-29%) are those that define the covert delinquency factor.
