We have presented a number of areas of investigation that will be important to test with genes emerging from large-scale GWAS studies. However, we note that these areas of study will present their own set of challenges. We must use the knowledge we have gained from the history of gene identification to inform post-GWAS studies. It will be critical for studies addressing the complex questions delineated in this review, involving how measured genetic risk unfolds across development, in conjunction with the environment, and in different groups, to be well-powered to detect genetic effects of reasonable and justified effect sizes. Fortunately, these studies will not require the sample sizes necessary for original gene identification; however, power should be addressed nonetheless. In addition, as has become routine in genetic studies, it will be key to build in replication samples. As has happened in the field of genetics, this will necessitate researchers who have traditionally worked within their own samples to come together to build collaborations. Many psychologists have longitudinal samples with rich phenotypic data, and to which genotypic data collections have been
