I read a few studies a while back that were able to predict if a person self identified as conservative or liberal based off of their brain patterns that were measured. I believe the the distinct areas were the right amygdala (handles instictual behaviour) and the left anterior cortex (which I think was used for intepreting how others will behave). Use of one part decreased the use of the other part. Scientist were able to successfully predict the right amygdala was associated with conservatives about 85ish% and anterior cortex for self identified liberals.

Other studies show that decreased use of the left anterior cortex is associated with childhood abuse (either physical or emotional), so it is reasonable to believe most conservatives had emotional/physical abuse during childhood that left them with an underdeveloped brain. Unfortunantly studies show there is very little that can be done to fix this deficiency once the person reaches mid to early twenties.

I guess the point is that they are not necessarily psychopaths, but they do have defective brain processes and we should improve systems and education that will help reduce childhood abuse, and teach empathy in schools if we want to reduce the quantity of right wingers.