Development and Psychopathology

Research Article

Genetic expression outside the skin: Clues to mechanisms of Genotype × Environment interaction

David Reissa1 c1 and Leslie D. Levea2

a1 Austen Riggs Center

a2 Oregon Social Learning Center


The rapidly moving study of Gene × Environment interaction (G × E) needs interim conceptual tools to track progress, integrate findings, and apply this knowledge to preventive intervention. We define two closely related concepts: the social mediation of the expression of genetic influences and the interaction between the entire genotype and the social environment (G × E). G × E, the primary focus of this report, assesses individual differences in the full genotype using twin, sibling, and adoption designs and, for the most part, employs fine-grained analyses of relational processes in the social environment. In comparison, studies of Allele × Environment interaction assess the influence on development of one or more measured polymorphisms as modified by environmental factors. G × E studies build on work showing how the social environment responds to genetic influences and how genetic influences shape the social environment. Recent G × E research has yielded new insight into variations in the sensitivity of the social environment to genotypic influences and provides clues to the specificity and timing of these environmental responses that can be leveraged to inform preventive interventions aimed at reducing genetic risk for problem behavior.


c1 Address correspondence and reprint requests to: David Reiss, Austen Riggs Center, 25 Main Street, PO Box 962, Stockbridge, MA 01262-0962; E-mail:


This paper summarizes the theoretical background for the Early Growth and Development Study, a prospective adoption study for assessing mechanisms of Genotype × Environment interaction (Grant 5 R01 HD 42608 from the National Institute of Child Health and Human Development and the National Institute on Drug Abuse, David Reiss, Principal Investigator). The Co-Investigators are Rand Conger, Xiaojia Ge, Leslie Leve, Jenae Neiderhiser, John Reid, Laura Scaramella, and Daniel Shaw, all of whom contributed to the conceptualization and design of the study. We also remember, with gratitude, the work of Remi Cadoret and Beverly Fagot, who contributed to the development of this project in the concluding years of their lives.