Given these limitations, additional studies of this important relationship are needed. Future research should test whether these findings replicate in other samples. Selected samples with higher rates and greater severity of maltreatment and conduct problems may be particularly informative, although recruiting highly selected twin samples would be difficult. Studies of data collected from multiple reporters would decrease measurement error and reduce any inflation in correlation due to common rater bias across measures. Future research should also assess the extent to which common shared- and twin-environmental influences on the relationship between maltreatment and conduct problems reflect passive gene-environment correlation and true environmental mediation. This could be done by studying twin pairs who are parents, which would test the effect of parents’ genes on the provision of parenting rather than the effect of children’s genes on the elicitation of parenting.
