political views and genetics

Tomorrow is of course the US elections, so a few thoughts about politics from a scientific point of view... A few days ago the AP ran a story about a possible genetic basis for political views. Coincidentally, the same day I learned about the research done by a social psychologist in my department on a possible psychological basis for political (and related) views. Let me fill you in on both of these.

First, the genetics. A professor named John Hibbing at the University of Nebraska has studied the political views of twins, fraternal and identical. Twin studies are a standard way of learning how much of a particular skill or personality trait is genetic and how much is environmental. (There is some controversy.) Identical twins share essentially all of their genetic material, while fraternal twins share only half of their genetic material. To the extent a pair of identical twins share traits/skills/whatever more so than do fraternal twins, then it's known that genetics accounts for a portion of the variation in traits/skills/whatever. So, for example, identical twins are considerably more likely to both be gay or both be straight than fraternal twins, so it's been concluded that homosexuality is partially genetic (and partially environmental) in cause. Hibbing followed on some earlier work that had shown significant genetic effects on social attitudes such as conservatism and religion. His new work looked at attitudes towards a series of specific political policies and views, and found that all of them had non-zero heritability. (Heritability is measured on a scale of "variance accounted for" from 0 to 1, where 0 means entirely environmental and 1 means entirely genetic, ala eye color.) In fact, heritable attitudes ranged from .18 on the low end, for attitude towards liberals, to .41 at the high end, for school prayer and property taxes. Interestingly, abortion is towards the low end, with only .25 heritability. Attitudes towards Republicans are notably more heritable (.36) than attributes towards Democrats (.26)! Hibbing speculates that genetics cause personality traits that lead people to be "absolutist" or "contextualist" (labels that roughly correspond to "conservative" and "liberal" in the US) and notes that the substantial genetic basis for political attitudes does not give much hope for a genuinely unifying political movement.

John Jost at NYU does work that fills in the gap between genes and political views. He explains his research program thusly:

Most of my work focuses on theoretical and empirical implications of a system justification theory... There are two major goals of system justification theory... The first goal is to understand how and why people provide cognitive and ideological support for the status quo, even when their support appears to conflict with personal and group interests. The second is to analyze the social and psychological consequences of supporting the status quo, especially for members of disadvantaged groups.

System justification theory addresses the holding of attitudes that are often contrary to one's own self-interest and therefore contrary to what one would expect on the basis of theories of self-enhancement or rational self-interest. Thus, our research focuses on counter-intuitive outcomes, such as the internalization of unfavorable stereotypes about one's own group, nonconscious biases that perpetuate inequality, attitudinal ambivalence directed at fellow ingroup members who challenge the system, opposition to equality among members of disadvantaged groups, rationalization of anticipated social and political outcomes, and tendencies among members of powerless groups to subjectively enhance the legitimacy of their powerlessness and, in some cases, to show greater support for the system than do members of powerful groups.

That is to say, he has been developing a psychological answer to the question "What's the Matter with Kansas?" In a recent paper (pdf), Jost and a colleague review a number of these system justification ideologies, including the Protestant work ethic and political conservatism. They note several personality traits that are linked to system justification, including "need for order, structure, and closure", and (the inverse of) "openness to experience." As many personality traits are about 50% genetically linked, this clearly suggests a genetic propensity for system justification views, and thus political attitudes.

Clearly, these two lines of research are coming to the same conclusion, that most people don't vote their strict personal self-interest, and the reasons why they do vote have substantially to do with personality traits that are partially genetic. As Lakoff has pointed out, the Democrats assume that people vote rationally on pocketbook issues, an assumption that is probably not justified.