syndromes. The unique variance in the symptoms of each disorder were largely due to non-shared environmental effects or error in the psychometric sense (i.e., unique idiosyncratic variation in a variable that does not correlate with other variables). The only significant correlations were the residual scores for neuroticism net of internalizing; MZ correlations were .23, while DZ correlations were .04. This indicates that there are genetic effects on neuroticism that are unique to the trait and not shared in common with the overall internalizing factor.
