“… Compared with liberals and moderates, conservatives score significantly higher on psychological instruments designed to measure epistemic needs for order, structure, simplicity, certainty, and closure, and they score significantly higher on instruments designed to measure the intensity of existential concerns such as fear of death and perceptions of a dangerous world (…). In terms of basic personality dimensions, liberals (and leftists) score significantly higher on Openness to New Experiences, and their greater open-mindedness manifests itself in terms of creativity, curiosity, novelty, diversity, and interest in travel. By contrast, conservatives (and rightists) score higher on Conscientiousness, and they are generally more orderly, organized, duty-bound, conventional, and more likely to follow rules …” — <http://www.stat.columbia.edu/~gelman/stuff_for_blog/jost2.pdf>

“… In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, where as individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats. …” —  <http://www.stat.columbia.edu/~gelman/stuff_for_blog/oxley.pdf>

My critique of the first guy’s work is that he is unsympathetic to one side of the dialect. That said his data appears pretty robust. For the second quote: given what we know about how plastic the brain is it seems difficult to reach any useful conclusion about causality. It is an actionable assortment of symptoms.