This article analyzes the contribution of genetics and the environment to educational attainment, occupational status, and income using data from over 1,100 monozygotic and 400 dizygotic Australian twin pairs aged from 18 to 99. The respective heritability estimates were 0.54, 0.37, and 0.18. The bivariate heritabilities were 0.71 for educational attainment and occupational status, 0.37 for education and income, and 0.61 for occupational status and income. There were no gender and cohort differences in the heritabilities for education and occupation, but for income, contrary to expectations, the heritabilities were significantly higher among women and for the older cohort (aged 50 or older). The sizable contribution of genes to these socioeconomic outcomes suggests that standard sociological and economic theories on the socioeconomic career require substantial modification to accommodate the role of genetics.

Attitudes towards foreign policy have typically been explained by ideological and demographic factors. We approach this study from a different perspective and ex amine the extent to which foreign policy preferences correspond to genetic variation. Using data from the Minnesota Twin Family Study, we show that a moderate share of individual differences in the degree to which one's foreign policy preferences are hawkish or dovish can be attributed to genetic variation. We also show, based on a bivariate twin model, that foreign policy preferences share a common genetic source of variation with political ideology. This result presents the possibility that ideology may be the causal pathway through which genes affect foreign policy preferences.