The highlighted SNP in zone 2 is consistent with the social push perspective in which genetic effects emerge as more salient in the healthier environments; this SNP has an effect of roughly 4 (e.g., BMI increases by four units for each risk allele) for college graduates, but it is virtually zero for those without a college degree. A similar conclusion could be reached for SNPs in zone 7 of this panel in which the SNP would have an effect (albeit negative) for those with a college degree but not for those without a degree. Zones 4 and 5 are those in which the effect of the SNP is very large for non–college graduates but much smaller for college graduates. In this case, the distribution of effects is in line with the diathesis-stress model. For example, there is one observed SNP that increases BMI by roughly six units for each risk allele among those without a college degree but is unrelated to BMI for those with a college degree. Figure 4 illustrates the difficulty in testing the diathesis-stress (zones 4 and
