us to eventually provide aggregate measures of both environmental and genetic risk, which could prove useful in tailoring prevention or treatment efforts. Additionally, because gene-environment correlation is also important, research designs leveraging information from natural experiments, such as a change in policy or a natural disaster, will increase our ability to differentiate processes of rGE from GxE (Schmitz & Conley, 2017). For example, research on the effect of veteran status, using the Vietnam Draft lottery as an instrumental variable, found that veterans with higher polygenic scores were more likely to initiate tobacco use and smoke more heavily (Schmitz & Conley, 2016).
