by Jonah Shepp
Chris Mooney reviews John R. Hibbing, Kevin B. Smith, and John R. Alford’s Predisposed: Liberals, Conservatives, and the Biology of Political Differences:
As Hibbing et al. explain, the evidence suggests that around 40 percent of the variation in political beliefs is ultimately rooted in DNA. The studies that form the basis for this conclusion use a simple but powerful paradigm: they examine the differences between pairs of monozygotic (“identical”) twins and pairs of dizygotic (“fraternal”) twins when it comes to political views. Again and again, the identical twins, who share 100 percent of their DNA, also share much more of their politics.
In other words, politics runs in families and is passed on to offspring. Hibbing and his coauthors suspect that what is ultimately being inherited is a set of core dispositions about how societies should resolve recurring problems: how to distribute resources (should we be individualistic or collectivist?); how to deal with outsiders and out-groups (are they threatening or enticing?); how to structure power relationships (should we be hierarchical or egalitarian?); and so on. These are, of course, problems that all human societies have had to grapple with; they are ancient. And inheriting a core disposition on how to resolve them would naturally predispose one to a variety of specific issue stances in a given political context.
He also looks at Avi Tuschman’s Our Political Nature, which takes the same argument further:
Tuschman doesn’t hold back. Conservatives, he suggests in one of three interrelated evolutionary accounts of the origins of politics, are a modern reflection of an evolutionary impulse that leads some of us to seek to control sexual reproduction and keep it within a relatively homogenous group. This naturally makes today’s conservatives more tribal and in-group oriented; if tribalism does anything, it makes it clear who you are and aren’t supposed to mate with.
Tuschman’s liberals, in contrast, are a modern reflection of an evolutionary impulse to take risks, and thereby pull in more genetic diversity through outbreeding. This naturally makes today’s liberals more exploratory and cosmopolitan, just as the personality tests always suggest. Ultimately, Tuschman bluntly writes, it all comes down to “different attitudes toward the transmission of DNA.” And if you want to set these two groups at absolute war with one another, all you need is something like the 1960s.
Arnold Kling thinks this type of scholarship is overhyped:
Mooney leaves readers with the impression that psychologists explain a larger share of political differences than they themselves claim to explain. In contrast, my guess is that they explain less. These are the sorts of studies that tend to suffer from publication bias (20 studies are tried, one out of 20 passes the “significance test” of having a 5 percent probability of being true by chance, and that study gets published). In these sorts of studies, attempts at replication sometimes fail completely, and even when successful the effects are smaller than in the original published study.
In fact, my guess is that we are approaching peak political psychology. I would bet that ten years from now the links between political beliefs and psychological traits will be regarded as a very minor field of inquiry.
In his own review, Kling panned Our Political Nature:
Overall, the pattern is that for Tuschman, every evil of conservatives is essential, by which I mean that it follows directly from the conservative point of view. On the other hand, every evil of the left is accidental, meaning that it occurs in spite of what leftists believe.
And yet, Tuschman declares early on that he will not take an ideological position, but instead he will speak objectively. To me, this lowers his credibility. It would have been more persuasive had he simply said at the outset, “I think that conservatives are racist, authoritarian, and warmongering, and here is some psychological research that supports my point of view.”