to vary both across difference studies and when the distribution of the outcome variable changes as the result of a non-linear transformation. An additional related complication is that, just like the complex traits of interest in GxE studies (including alcohol use related behaviors), these measured environments have no “true metric” (Dick et al., 2015). Therefore, each measurement of an environment may (or may not) tap into one (or multiple) aspects of the environment that are relevant to the development of the complex trait.
