I've gotten less political here as the U.S. presidential election draws near. But I just have to comment on this bone-headed study, described in a Houston Chronicle story with the asinine title "Liberal versus conservative: DNA may tell."
What are the problems with the study? First, the research methods are flawed, because the concepts of "liberal" and "conservative" are very subjective and specific to modern United States culture. And second, the conclusion reached by the researcher being interviewed is far more than what is supported by the data.
The researchers started by having their sample fill out questionnaires on social policies such as "support for the war in Iraq, support for or opposition to immigration, opposition to gun control, [and] support for the death penalty." Each of these is a complex issue with nuanced arguments, about which many people have complex opinions, but since they were part of a questionnaire, it is likely that ratings were obtained simply on a polarized scale. My own opinion on the death penalty, for instance, cannot be classified into simple support or oppose; it would take me at least a couple of paragraphs to explain it.
The issues were categorized into "socially protective" and non-"socially protective" policies, about which the interviewee says "certainly there's a left-right orientation." Being themselves mired in American political culture (the study took place at Houston's Rice University), the researchers apparently cannot even see their own bias in labeling the various policies as "left" or "right." To them, "socially protective" policies are right-wing, not left-wing — even though in some cases, policies considered liberal could be seen as more "socially protective" than the corresponding conservative policies.
For example, the researchers considered opposition to gun control, classically a conservative position, as a "socially protective" policy, which fits their data (which I will get to below). Yet arguments in favor of gun control, classically liberal, always have a socially protective pitch; if not to protect innocent people from being killed by guns, why restrict them?
The biases of the researchers make the data worthless for the purpose the researchers are seeking — determining whether one's place on the political spectrum has at least a partial biological basis. Yet even if the data were good, the conclusion announced by the interviewee is on another planet from what those data actually show.
What the data show is that people who favor "socially protective" policies (the ones pre-defined as "conservative") have stronger physiological responses to anxiety-provoking situations (disturbing images and startling sounds) than those who do not favor those policies. Physiological response to stress is strongly tied to psychological factors whose biological basis is unclear at best. But the interviewee cites some concrete numbers, apparently pulled out of thin air: "Probably two-thirds of the explanation is outside of biology," with the rest based on specifically on DNA. Keep in mind that this study did not look at genetic factors at all. There is absolutely no support for saying that correlation between biology and politics, if it exists at all, is based on DNA rather than on environmental effects on one's biology. In other words, there is no investigation into whether the results come from nature or from nurture. (In fairness, this conclusion is not presented in the abstract of the study itself.)
This study was published in the prestigious journal Science, yet almost all of the researchers hail from the field of political science. Only two of the eight authors have any background in psychology, and only one of those is clearly identified with biological psychology. As with some other journal articles, how this nonscientific rubbish passed peer review is a mystery.