I figured the recent post on conservatives and the amygdala, and liberals and the anterior cingulate cortex (ACC), wasn't controversial enough. So why not go farther and discuss recent research that ties our political views to our genes? I point you to the following paper: Peter K. Hatemi et al (there is a long list of als), "A Genome-Wide Analysis of Liberal and Conservative Political Attitudes," recently published (2011) in the Journal of Politics. A PDF of the paper can be found here. And here is the abstract:
The assumption that the transmission of social behaviors and political preferences is purely cultural has been challenged repeatedly over the last 40 years by the combined evidence of large studies of adult twins and their relatives, adoption studies, and twins reared apart. Variance components and path modeling analyses using data from extended families quantiﬁed the overall genetic inﬂuence on political attitudes, but few studies have attempted to localize the parts of the genome which accounted for the heritability estimates found for political preferences. Here, we present the ﬁrst genome-wide analysis of Conservative-Liberal attitudes from a sample of 13,000 respondents whose DNA was collected in conjunction with a 50-item sociopolitical attitude questionnaire. Several signiﬁcant linkage peaks were identiﬁed and potential candidate genes discussed.
The technology used, "genome-wide linkage," is one that the authors say was used to locate the BRACA1 and BRACA2 genes linked to breast cancer.... Basically, all the subjects (13,201) had completed the aforementioned political attitudes questionnaire and had given blood. Then there was an attempt to find chromosomal regions with polymorphisms--i.e., these regions vary in people--where the variance correlated with political views. The rather amazing result--for any of us who stops to think about the incredibly vast distance between the genes we are born with and our political attitudes as adults--was that three regions were found to be linked in a way that was "significant" (one reaching the most stringent test of it) and one was linked in a way that was "suggestive." (The technical stuff on all of this is in the paper.) What could this mean? Well, as the authors write:
As we identified four regions of interest, and one that meets the strictest criteria, our ﬁndings are consistent with what might be expected if the genetic component of variation in Conservatism-Liberalism resembles any other polygenic human trait, for which the genetic resemblance between relatives can only be resolved reliably into the effects of a large number of genes with small effects that typically cannot be identiﬁed by linkage.
In other words, no gene is acting directly to determine our political views--there is no "liberal" or "conservative" gene--but there might be a combination of genes acting together that somehow predispose us to have particular politics, presumably through their role in influencing our brains and thus our personalities or social behaviors. Indeed, the most promising gene regions turned up in the study all involved "NMDA and glutamate related receptors." The authors couldn't resist speculating here:
Thought organization, information processing, capacity for abstract thought, learning, and performance are related to blockage of NMDA. Of particular interest to political ideology is the relationship between NMDA and performance on the Wisconsin Card Sorting Test (WCST). The WCST is a neuropsychological test of the ability to display flexibility in the face of changing schedules of reinforcement. By definition Conservatism and Liberalism have much to do with flexibility of opinion in the face of a changing world.
These are highly exploratory results. The scientists can't even say that they identified, for sure, a single the genetic pathway that influences our political views. But at the same time, the genome wide fishing expedition didn't turn up empty. They caught some things that will definitely be subjected to further research. What's the big picture? Here are the authors again:
To ﬁnd a signiﬁcant linkage region that may implicate certain genetic markers is not to say that a particular gene determines a particular behavior. Nor do our results advocate that genes have some greater effects than that of the environment. This is certainly not the case. Rather, we are starting from two opposite ends of a very complex process: DNA, somewhere near the very basic matter of what living organisms are made of on one end; and an expressed complex behavior (political ideology) on the other. Behavior is the ﬁnal end product of all that goes in and out of what it is to be human, interacting in a complex and changing environment during one’s lifecycle (e.g., puberty, menopause, etc.). We have barely begun to understand what goes on in between those two spaces, which makes this area of research exciting, while also inspiring caution. The understanding that we cannot yet accurately map how genes inﬂuence brain processes and biological mechanisms which in turn interact with our upbringing, social life, personal experience, the weather, diet, etc, to somehow be expressed in part as a ConservativeLiberal orientation, is the exact reason that genomewide analyses are valuable and necessary for political science. Human behavior emerges from the interaction and interplay of genes, socialization and environmental stimuli, working through ontogenetic neurobiological processes embedded in an evolutionary framework (Dobzhansky 1973). So far as the data suggest, a theory and method which includes genetic inﬂuences, no matter how large or small, accounts for portions of Conservative-Liberal orientations that environment-only models do not.
I truly find this amazing. But, if this is what the science says for now, there is only one thing to do: more science.