Genetic and phenotypic associations between political ideology and fertility

Much secondary literature has reported a positive correlation between conservatism and fertility, but there only exists a small empirical basis for this finding. Using data from the General Social Survey, we again see this... [ view full abstract ]

Much secondary literature has reported a positive correlation between conservatism and fertility, but there only exists a small empirical basis for this finding. Using data from the General Social Survey, we again see this trend of conservatism correlating with increased number of children; this association motivates our endeavor to understand the sources of the relationship. In the present work, we study the relationship between traditionalism and fertility. Traditionalism is a measure of the adherence to traditional customs or beliefs, a construct closely related to social conservatism. Fertility is defined as the number of children ever born. The phenotypic data comes from the Minnesota Center for Twin and Family Research; the genetic data from the human reproductive behavior (fertility) GWAS (Barban et al., 2016). We attempted to predict traditionalism with a fertility polygenic score (PGS). However, the PGS analysis was insignificant. The null result is possibly due to the insufficient sample sizes of the GWAS and validation samples resulting in small statistical power. Fertility is highly polygenic trait: because most other traits or behaviors influence fertility, it is likely shaped by a manifold of genetic variants.