the stability of the relationships across groups and suggest potentially different etiologies. When effect sizes are consistent across groups, this provides support for the generalizability of the genetic-phenotypic relationships. When effect sizes differ across groups, this suggests the possibility of additional genetic and environmental explanations for the relationship, including gene-environment effects; furthermore, in the case of candidate genes when the function of the gene is not established, group differences may be due to ethnic group differences in linkage disequilibrium of the initially identified gene with an actual functional gene.
