Thomas B. Edsall in the NYT
In “Obedience to Traditional Authority: A heritable factor underlying authoritarianism, conservatism and religiousness,” published by the journal Personality and Individual Differences in 2013, three psychologists write that “authoritarianism, religiousness and conservatism,” which they call the “traditional moral values triad,” are “substantially influenced by genetic factors.” According to the authors — Steven Ludeke of Colgate, Thomas J. Bouchard of the University of Minnesota, and Wendy Johnson of the University of Edinburgh — all three traits are reflections of “a single, underlying tendency,” previously described in one word by Bouchard in a 2006 paper as “traditionalism.” Traditionalists in this sense are defined as “having strict moral standards and child-rearing practices, valuing conventional propriety and reputation, opposing rebelliousness and selfish disregard of others, and valuing religious institutions and practices.”
Working along a parallel path, Amanda Friesen, a political scientist at Indiana University, and Aleksander Ksiazkiewicz, a graduate student in political science at Rice University, concluded from their study comparing identical and fraternal twins that “the correlation between religious importance and conservatism” is “driven primarily, but usually not exclusively, by genetic factors.” The substantial “genetic component in these relationships suggests that there may be a common underlying predisposition that leads individuals to adopt conservative bedrock social principles and political ideologies while simultaneously feeling the need for religious experiences.”
From this perspective, the Democratic Party — supportive of abortion rights, same-sex marriage and the primacy of self-expressive individualism over obligation to family — is irreconcilably alien to a segment of the electorate. And the same is true from the opposite viewpoint: a Republican Party committed to right-to-life policies, to a belief that marriage must be between a man and a woman, and to family obligation over self-actualization, is profoundly unacceptable to many on the left.
If these predispositions are, as Friesen and Ksiazkiewicz argue, to some degree genetically rooted, they may not lend themselves to rational debate and compromise.