Gene-Environment Interplay in Adulthood.

Abstract

The topic of gene–environment interplay has long been of interest to behavioral geneticists (Waddington 1942). In the 1970s, much of the critique of BG studies rested on the assumption in many biometrical models that there was no G9E interaction or GE correlation. The ability to test GE interplay has varied largely based on whether or not the models are solely based on anonymous variance components, or whether one has a measured G or a measured E. Indeed, adoption models were long thought to be the only way to get at GE correlation in absence of measured G or E. With the advent of the moderation model by Purcell (2002) and improvements (Van der Sluis et al. 2008), a wave of interest in using moderator models began, where variance components could be tested as a function of a particular ‘‘environment.’’ Even more attention was brought to the field when Caspi et al. published their findings in Science (2003), with a specific candidate gene and a variety of measures of E, i.e. stressful life events, on multiple indicators of depression and depressive symptoms. The Behavior Genetics Association has seen an increase in presentations addressing various forms of GE interplay, not the least at the association’s annual meetings. For example, in 1995 there were only two papers at the annual meeting that addressed GE interplay, and at that time most of the work was conducted using mouse models of behavior. The number of papers focusing on various forms of GE interplay in humans slowly increased over the following years (5 in 2000, 8 in 2005). The 2010 conference marks one of the first instances of the phrase ‘‘gene– environment interplay’’ appearing in the program (Arvey et al. 2010). By the 2015 conference, there were 18 papers and posters addressing GE interplay, using a variety of methodologies and applied to several phenotypes across the lifespan. We felt that the burgeoning production of papers related to GE interplay in humans, extending the methods and issues into adulthood, was worthy of a special issue of Behavior Genetics.