Casey A. Klofstad • Rose McDermott • Peter K. Hatemi
Abstract: American politics has become more polarized. The source of the phenomena is debated. We posit that human mate choice may play a role in the process. Spouses are highly correlated in their political preferences, and research in behavioral genetics, neuroscience, and endocrinology shows that political preferences develop through a complex interaction of social upbringing, life experience, immediate circumstance, and genes and hormones, operating through one’s psychological architecture by Hatemi et al. (J Theor Politics, 24:305–327, 2012). Consequently, if people with similar political values produce children, there will be more individuals at the ideological extremes over generations. This said, we are left with a mystery: spousal concordance on political attitudes does not result from convergence over the course of the relationship, nor are spouses initially selecting one another on political preferences. We examine whether positive mate assorta- tion—like seeks like—on non-political factors such as lifestyle and demographics could lead to inadvertent assortation on political preferences. Using a sample of Internet dating profiles we find that both liberals and conservatives seek to date individuals who are like themselves. This result suggests a pathway by which long- term couples come to share political preferences, which in turn could be fueling the widening ideological gap in the United States.
The authors hypothesize that notable differences would be apparent up after 5 generations.