GxE interaction are statistically indistinguishable. The key concept is one of dependence: one cannot understand the effect of genes without taking into account the environment, and one cannot understand the effect of the environment without taking into account genetic predispositions. The implications of this dependency are profound and may hint toward why the concept of GxE interaction was met by so much resistance (or ignored) by the fields of development and genetics, respectively, for so long. Most scientists are trained in one area—psychology OR genetics—so the very notion of GxE interaction forces one to recognize and incorporate other areas of science into one’s own research. This can be difficult! Yet I propose that this is also where the most exciting advances are likely to happen.
