This review has largely focused on basic genetic concepts that are critical for social scientists to understand when incorporating genetic components into their research. But we would be remiss to leave the reader with the impression that teaming up with geneticists will provide clear answers about the way forward. The rapidly changing landscape in the field of genetics and constant advances in the tools used for gene finding have raised nearly as many questions as they have provided answers. GWAS have not been wildly successful in psychiatric and behavioral phenotypes, raising question about why this is the case, as other common complex, polygenic disorders have enjoyed greater success (e.g., with GWAS mapping many novel loci for Crohn's disease and type 2 diabetes; McCarthy et al., 2008). However, even in disorders that have enjoyed more success in mapping risk loci, the variants that have been identified only account for a very small fraction of the heritability. This has been called the “missing heritability problem” (Manolio et al., 2009), and several potential explanations have been put forth for this phenomenon, including the
