Developing databases to conduct large-scale genome-wide gene-by-intervention interaction research in the field of human capital development depends on two key ingredients. First, randomized trials of interventions must collect genetic data from participants and obtain consent for the use of these data in post hoc analyses. Second, investigators running randomized trials must participate in collaborative networks to share data. Consortia are necessary because genetic influences on the outcomes targeted by human capital interventions are complex and magnitudes of individual genetic effects are likely to be very small (Benjamin et al., 2012; Chabris et al., 2012). Consortia are possible, as illustrated by a recent genome-wide association study of educational attainment that integrated dozens of datasets to achieve a sample of hundreds of thousands of individuals (Rietveld et al., 2013). Consortia are worth the effort as evidenced by their track record in the biomedical science where, despite high complexity of genetic influences on the outcomes studied, thousands of discoveries have been made (www.genome.gov/gwasstudies) and clinical applications translating these discoveries are beginning to emerge (Manolio, 2013).
