adoption study

n. A method used in trying to distinguish between the effects of genetics and environment in which children separated from their parents shortly after birth and raised in an adopted family are compared with genetic relatives and with other members of the family in which the children are raised. If the genetic influence on a specific trait is high, it is assumed that there will be a higher correlation between the children and their biological relatives, while if the genetic influence is weak, there will be a greater correlation with the families in which the children have been raised. Among the many difficulties in such studies is the lack of randomness of both selection of children to be adopted and the households which adopt them and the fact that most children are not separated from their biological families at birth but after a significant amount of time has elapsed since birth.