There have been radical shifts as to belief about whether human behavior is more strongly determined by genes or by environment over the course of scientific history. Different fields seemingly advocated for the importance of one over the other (the so-called nature versus nurture debate), with some camps studying genetic influence and others studying environmental factors. It is now widely accepted that both genetic and environmental influences are important, and characterizing how these influences come together to impact outcome, ie the study of gene-environment interaction (GxE) has become an important area of study across multiple disciplines. That said, few research topics have generated more controversy and less clarity than the study of candidate gene by environment interaction (cGxE) in complex behavioral outcomes. Following the publication of cGxE studies in high profile scientific journals (Caspi et al., 2002; Caspi et al., 2003), the last decade has witnessed an explosion of interest in this area. There has been an exponential increase in the number of cGxE studies published, with researchers from diverse backgrounds routinely incorporating cGxE components into their studies. However, there
