polygenic score for the externalizing phenotype remains modest. In addition, in our genetic nurturance analyses, the mediating effect via parental externalizing psychopathology was of small magnitude, though comparable to the genetic nurturance analyses for substance use phenotypes reported in Saunders et al. (2021). Future studies should explore and identify other possible environmental mediators of genetic nurture effects. Finally, our results are observational in nature and should not be interpreted as causal pathways.
