https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3092984/ For those that don't know: The anterior cingulate cortex (ACC) is involved in certain higher-level functions, such as reward anticipation, decision-making, ethics and morality, impulse control, and emotion. The right amygdala plays a role in the association of time and places with emotional properties (in particular, fear and disgust). It is, in large degree, responsible for the formation of memories following strong emotional states. So... basically, it boils down to - Conservatives are more emotionally driven, where as Liberals are more motivated by ethics and morality. A curious finding, and of course correlation doesn't necessitate causation... but it makes sense. After all, it explains why Fox and co have such success using fear mongering to control and influence their viewers.
A few more studies for reference: http://yoelinbar.net/papers/disgust_conservatism.pdf http://faculty.virginia.edu/haidtlab/jost.glaser.political-conservatism-as-motivated-social-cog.pdf http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0059837 http://www.danielmtfessler.com/wp-c...-in-press-Political-Orientation-Credulity.pdf