Ideological orientations are substantially heritable, but the public is largely non-ideological; what happens is that ideological orientations are extraordinarily heritable for the most informed citizens, much less for the others

Genes, Ideology, & Sophistication. Nathan P. Kalmoe. Jan 2020. https://www.dropbox.com/s/4q14j1qwx94ub7d/Kalmoe%20-%20Genes%2C%20Ideology%2C%20%26%20Sophistication.pdf?dl=0

Abstract: Twin studies show that ideological orientations are substantially heritable, but how does that comport with evidence showing a largely non-ideological public? This study integrates these two important literatures and tests whether political sophistication is necessary for genetic predispositions to find expression in political attitudes and their organization. Data from the Minnesota Twin Study show that ideological orientations are extraordinarily heritable for the most informed citizens—far more so than full-sample averages in past tests show—but barely heritable among the rest. This holds true for the Wilson-Patterson ideological index scores and a related measure of ideological consistency, and somewhat less so for individual W-P items. Heritability for ideological identification is non-monotonic across knowledge; partisanship is most heritable for the least knowledgeable. The results resolve the tension between the two fields by showing that political knowledge is required to link genetic predispositions with specific attitudes.


DISCUSSION
I set out to test whether average heritability estimates differ by levels of political knowledge, as prodigious literature on the limits of mass belief systems suggest they might. The results grandly support these expectations: High-knowledge twin pairs (top 21%) show heritability estimates ranging from 49-82% (average 65%) across a variety of ideology estimates. In contrast, the least knowledgeable half of the sample showed comparable estimates of 0-40% (average 18%). To sum it up: ideological orientations appear extraordinarily heritable for the most sophisticated citizens—far more so than full-sample averages in past tests show—but hardly heritable at all among the rest.

How well does this twin sample reflect the national population? Arceneaux and colleagues (2012) show Minnesota Twin Study respondents are older and more educated than the American public, on average, but they are similarly interested in politics and similarly unconstrained in attitudes, like national samples. That suggests these tests are a reasonable base from which to infer general population dynamics, at least as they relate to political sophistication.

Converse (2000) argued that ideological tests must always account for the public’s huge
variance in political knowledge—and that doing otherwise risked concealing more than it revealed.
Simply put, average ideological estimates ignore qualitative differences in the nature of belief
systems. The tests here show the utility of extending Converse’s exhortation to estimates of genetic influence. Low-knowledge citizens may also carry heritable ideological predispositions, but those proto-orientations lie dormant without the sophistication and engagement to connect them to concrete sociopolitical attitudes and broader liberal-conservative belief systems. Political knowledge is necessary for that political development. Merging two important and related but isolated fields adds insight into the origins of ideological beliefs and the conditions for genetic influence in politics.