Genetic effects on 'environmental' measures: Consequences for behavior-genetic analysis

Abstract

Dr. Plomin is one of the most accomplished human behavior-geneticists of the moment, as evidenced by the many valuable contributions to the field by him and his collaborators. Again, the present target article has some important implications, this time not only for behavior genetics, but also for mainstream psychology. P&B argue quite convincingly that certain measures often used by psychologists to assess environmental influences on a subject contain a genetic component. Hence, at least as long as indirect environmental measures are involved, these variables are not valid as such, but, rather, phenotypes amenable to genetic analysis. Unfortunately, P&B do not phrase their conclusions in this way. Although in the title of their target article the word 'environmental' is placed within quotation marks, in the rest of their target article they stick to this terminology. In my opinion, this is unfortunate and promotes confusion between some important concepts of genetic analysis.