Cons have larger fear centers in their brains.

Scientists at the University of London say that conservatives have an enlarged "fear" area in their brains, and smaller areas associated with courage and optimism. The London Telegraph reports:

Scientists have found that people with conservative views have brains with larger amygdalas, almond shaped areas in the centre of the brain often associated with anxiety and emotions.

On the other hand, they have a smaller anterior cingulate, an area at the front of the brain associated with courage and looking on the bright side of life.

The researches say there is a direct correlation between the sizes of those areas and one's political views.
http://www.salon.com/2010/12/29/conservative_brains/

Pathologizing Conservatism
Is it an unfortunate evolutionary holdover, or the product of bad upbringing?

Whether it be an unfortunate evolutionary holdover or a mental disease transmitted by our parents-the science is apparently still up in the air-academic researchers have surely amassed enough evidence of psychopathology that conservatism can listed in the next edition of the Diagnostic and Statistical Manual of Mental Disorders. Reasonable people, such as the distinguished academic researchers cited here, will no doubt agree that until effective treatments can be developed, we should reconsider whether sufferers of conservatism, like other mental defectives, should be allowed freely to exercise the franchise.
http://reason.com/archives/2004/10/20/pathologizing-conservatism

Researchers help define what makes a political conservative

Four researchers who culled through 50 years of research literature about the psychology of conservatism report that at the core of political conservatism is the resistance to change and a tolerance for inequality, and that some of the common psychological factors linked to political conservatism include:

* Fear and aggression
* Dogmatism and intolerance of ambiguity
* Uncertainty avoidance
* Need for cognitive closure
* Terror management
http://www.berkeley.edu/news/media/releases/2003/07/22_politics.shtml

Conservatism as a Mental Illness
Republicans have exhibited ten telltale signs of mental illness this past year
http://www.psychologytoday.com/blog/evolutionary-entertainment/201206/conservatism-mental-illness

Is Political Conservatism a Mild Form of Insanity?
Death Fear (among other unsavory attributes) Predicts Republicanism

Here are the facts. A meta-analysis culled from 88 samples in 12 countries, and with an N of 22,818, revealed that "several psychological variables predicted political conservatism." Which variables exactly? In order of predictive power: Death anxiety, system instability, dogmatism/intolerance of ambiguity, closed-mindedness, low tolerance of uncertainty, high needs for order, structure, and closure, low integrative complexity, fear of threat and loss, and low self-esteem. The researchers conclude, a little chillingly, that "the core ideology of conservatism stresses resistance to change and a justification of inequality."

The above list of variables is more than a little unsavory. We are talking about someone full of fear, with a poor sense of self, and a lack of mental dexterity. I always tell my students that tolerance of ambiguity is one especially excellent mark of psychological maturity. It isn't a black and white world. According to the research, conservatives possess precisely the opposite: an intolerance of ambiguity and an inability to deal with complexity. Maybe that's one reason why Obama seems so distasteful to them: he is a nuanced, multi-faceted thinker who can see things from several different perspectives simultaneously. And he isn't preaching fear, either.

http://www.psychologytoday.com/blog/genius-and-madness/200809/is-political-conservatism-mild-form-insanity