Political Behavior Blog

Already in 2004, Alford and Hibbing had published an article ambitiously titled "The Origin of Politics" in Perspectives. In that article, the authors endeavored to sketch out a "theory of the genetic origins of political behavior." More recently, Alford, Funk, and Hibbing (AFH) published a somewhat more modestly tited empirical article in the APSR - "Are Political Orientations Genetically Transmitted?" - which uses the results of twin studies to distinguish the environmental determinants of political attitudes from hitherto ignored inherited traits. Their arguments are greatly appealing: if we really do inherit behavioral as well as more "structural" traits - as biologists from Darwin onwards have widely believed and as recent advances in psychology seem to suggest - why not attitudes that may affect our political preferences?

The basic mechanism posited by AFH is that genetic factors shape behavior in interaction with environmental influences: particular genotypes do not determine behavior; however, our genes affect the extent to which an individual is sensitive to environmental influences on a varieties of behaviors. There is no single gene, moreover, that is singularly responsible for a particular attitude; rather, it is the complex web of chemical reactions in the brain shaped by our genetic make-up that may translate into particular predispositions.

It is quite obvious that the most difficult challenge the authors face is that of showing that specifically political attitudes are to a certain extent genetically determined. For instance, the dominance of the Left-Right dimension of party competition across so many world regions - dubiously cited by the authors as preliminary evidence for the fact that there is a "genetic component to political ideology" - is decidedly a recent phenomenon. As Caramani (2004) shows, the functional Left/Right cleavage - at least in Europe - is the result of 19th century party competition, not a constant feature of politics throughout human history. Distinctly political attitudes such as those that make up a leftist or rightist ideology have only been relevant for the past 100 years or so - definitely too short a period for natural selection to have shaped such attitudes. Rather, the link between genetics and political orientations is only plausible if such attitudes can be traced back to larger personality traits subject to evolutionary forces.

This seems precisely the line of attack chosen by AFH. "The heritability of social attitudes," in fact, is in their view "likely derivative of the heritability of various personality traits" - such as "general openness" - which may affect a host of political predispositions. The evidence marshaled by AFH generally supports the notion that political attitudes are to a varying extent inherited. Monozygotic (MZ) twins (who share 100% of their genetic make-up) have consistently more similar positions on a multitude of topics than Dizygotic (DZ) twins (who on average share only 50% of their genes). The authors do their best to exclude rival explanations dealing with different patterns of childrearing that may potentially confound the results; on this point, their evidence and arguments seem to be sufficiently persuasive. Nonetheless, some skepticism remains when one examines one of AFH's main assumptions - that any difference between MZ and DZ twins included in the study is entirely due to genetics. In other words, the two groups do not differ systematically on any other characteristic affecting political behavior.

It goes without saying that this assumption may potentially run into trouble - in the form of unbalanced samples - in the absence of random selection, but the authors pay little attention to that. Even more importantly,though, whether the correlations found may indeed be indicative of an underlying causal relationship remains questionable in the absence of a clear causal mechanism linking particular sets of genes with particular sets of attitudes. The process by which specific attitudes are shaped by genetics, therefore, remains largely a black box. I am aware that these criticisms may be perceived to be part of a "moving the goal post" strategy. If anything, though, my personal bias is in favor of the authors' arguments, as I consider this to be quite a promising research avenue. Far from rejecting the argument based on any instinctual (genetic?) aversion to the claims or abhorrence for their implications, I am simply wary of the article's key assumption, especially in the absence of a precise causal story. It goes without saying that asking AFH to account, in a single article, for the genes responsible for each of the attitudes they consider would be absurd. However, the absence of any such mechanism renders this article a promising beginning, rather than conclusive demonstration that any political orientation is genetically determined.