Gene x environment interaction and the moderating effect of adoption agency disclosure on estimating genetic effects

The present study utilized gene–environment (G×E) interaction to test for the potential biasing effects of adoptive parent recall of information disclosed to them about the biological parent on genetic estimates. Two independent adoption samples were combined for all analyses (n=496). Adoptive parent knowledge was the specific environmental effect and was comprised of three categories: none, physical and psychiatric medical. Biological parent alcoholism and antisocial personality were the specific genetic effects. Symptom counts of childhood and adult problem behaviors served as dependent variables. Eighteen 2 (adoptee sex)×2 (biological parent alcoholism or antisocial personality)×3 (adoptive parent knowledge) analyses of co-variance (ANCOVA) were conducted with separate analyses for biological alcoholism and antisocial personality as the genetic effect. Significant G×E interactions were found for models including either biological alcoholism or antisocial personality. The nature of the interactions were complex but generally supported the presence of a genetic effect only in the presence of either physical or psychiatric knowledge. The findings from the study indicate that behavioral geneticists who use the adoption paradigm to examine genetic and environmental predictors of behavior must recognize the potential bias produced by openness in adoptions.