from the study of twins show how genes influence economic choices:
We find strong evidence that economic preferences are heritable. For altruism as well as risk preferences the genetic effect is significantly different from zero. In our best fitting models, the point estimates suggest that 35 percent of the variation in altruism and 27 percent of variation in risk preferences is explained by genetic influences. Furthermore, our results suggest only a modest role for common environment as a source of phenotypic variation. We argue that the significance of these results extends well beyond documenting an important, but hitherto largely ignored, source of preference heterogeneity. For example, although it is widely accepted that parent-offspring correlations in isolation cannot be used to discriminate between theories of genetic and cultural transmission, much economic research is carried out under the presumption that genetic transmission is small enough that it can be ignored. Such an assumption is not consistent with our findings.