Defining the Environment in Gene–Environment Research: Lessons From Social Epidemiology

Abstract

In this article, we make the case that social epidemiology provides a useful framework to define the environment within gene-environment (G·E) research. We describe the environment in a multilevel, multidomain, longitudinal framework that accounts for upstream processes influencing health outcomes. We then illustrate the utility of this approach by describing how intermediate levels of social organization, such as neighborhoods or schools, are key environmental components of G·E research. We discuss different models of G·E research and encourage public health researchers to consider the value of including genetic information from their study participants. We also encourage researchers interested in G·E interplay to consider the merits of the social epidemiology model when defining the environment. (Am J Public Health.

Status Attainment and Social Mobility

“…However, contexts shaping gene expression are located also at more distal levels: In neighborhoods, educational and work contexts, and societal institutions. Up to now, these multilevel interdependencies have been researched little with respect to genetic influences (for notable exceptions see Boardman et al 2013;Branigan et al 2013). The proximate and distal levels do not work independently of one another but may constitute chains of risk generation and risk compensation over the life course.…”

Biological Determinism and Racial Essentialism

“…In gxE studies, researchers attempt to understand how environmental and genetic factors that influence a particular trait, behavior, or health outcome are conditional on one another (Boardman, Daw, and Freese 2013). Four general outcomes from the study of how environmental factors influence genetic differences are (1) little to no genetic differences as a result of an environmental cause;…”

“…Boardman, Daw, andFreese (2013) describe two variations of gxE research and one related outcome of studying the link between genetic and environmental factors. One variation of gxE studies is a heritability-environment (HxE) interaction population model whereby scientists estimate phenotypic variations across multiple environments by focusing on the differences among individuals and families within proximate environments.…”

“…One variation of gxE studies is a heritability-environment (HxE) interaction population model whereby scientists estimate phenotypic variations across multiple environments by focusing on the differences among individuals and families within proximate environments. The second variation of gxE studies is an allele-by-environment (AxE) interaction model in which scientists use environmental moderations to identify the connections between such environmental changes, specific alleles, and health outcomes (Boardman, Daw, and Freese 2013).…”

“…gxE studies also attempt to identify how genetic traits influence environments in gene-environment correlations (rgE) whereby a genetic trait may influence the selection of an environment (active rgE) or an environment may respond differently to a particular genetic trait (evocative rgE), which can establish a link between individual traits and specific outcomes as the result of environmental responses (Boardman, Daw, and Freese 2013). The latter gene-environment correlation is an example of the difficulties of interpreting gxE studies, as a supposed genetic influence on an outcome is a direct result of not the individual trait per se but environments changing to produce such outcomes based on a trait.…”