Summary: Our political differences rest on two fundamentally different perceptions of human nature and a resultant long-standing conflict in worldviews. Growing physical and anecdotal evidence now indicate that these conflicting perceptions likely have an innate neurological component and are, therefore. largely involuntary. (850 words)
In a previous essay some of the fundamental political differences separating Liberals and Conservatives were presented. These differences arise from conflicting worldviews based on different perceptions of man’s essential nature. But the larger question is why do people come to resolutely hold such philosophically conflicting views in the first place. That is the subject here.
A number of studies - recently aided by magnetic resonance imaging (MRI) and positron emission tomography (PET) brain scans - suggest the answer may lie in the prefrontal cortex of the brain: Our political biases are not just happenstance choices but result from predilections genetically embedded in the prefrontal cortex: they have a neurological and therefore heritable origin.
It was Roger Sperry  who was instrumental in demonstrating the laterality of the human brain. Sperry’s work, and subsequently that of many others, has demonstrated the “bicameral” nature of the cortex which consists of two conjoined symmetrical lobes or hemispheres. Sensory input is processed synergistically through these left and right lobes which synthesize a response.
While we all use our whole brain, many have a left or right lobe dominance which influences our personalities, learning styles and “colors” our perceptions of what we see and hear. Many such characteristics have been identified as intrinsic and relatable to one or the other of the two hemispheres. Some of these attributes  are tabled below.
Thinking Left Lobe Right Lobe
" Logical Intuitive
" Linear Random
" Rational Emotional
" Analytical Artistic
" Objective Subjective
" Detailed Holistic
" Disciplined Impulsive
" Practical Theoretical
Physical More gray matter More white matter
Behavioral Present & past Present & future
Gender predominance Male Female
The hypothesis here is that political bias is a result of whether the individual is right or left lobe dominant. The former would tend to perceive the world through a feelings oriented filter and respond from an emotional, intuitive and holistic perspective. He/she would be an Emotional Intuitive and likely to populate the imaginative-creative world of writers, actors, musicians, and the professions of teaching, journalism and the clergy: the “poet” class. Anecdotal evidence from recent national elections indicate that people in these intellectual professions predominantly support Left/Liberal political causes.
Does it follow from the above that left-lobe dominant individuals are likely to be more staid and traditionalistic in their socio-political mores? On average, do people who see the world through a more logical and objective prism find political expression as conservatives? The menu of Left lobe traits - logical, methodical, rule bound, disciplined and analytical - seems consistent with the characteristics of the Conservative/Traditionalist and the more by-the-numbers professions in which they predominate (e.g.; engineers, the military, police): the tradition-bound “warrior” class of more pragmatic Logical-Rationalists.
Some evidence supporting the above speculation has been reported . This evidence correlated differences in left-right political attitudes with differences in dopamine neurotransmitter systems. This is compelling evidence that distinct neurochemical factors are driving similarly distinct psychological characteristics. If future studies verify such brain hemisphere correlations with political attitudes the consequences would be significant. For one, the utter futility of persuasive political debate would be clear: no one gets their mind changed as anecdotal experience suggests. Trying to alter another’s political opinions through force of argument would be akin to trying to change his eye color . More importantly, the implications for the political Left would be sobering. The impact on the core belief of the Left that man is a malleable creature readily adaptable to behavioral makeover’s under the aegis of a “morally superior” leadership would be refuted absolutely. In contrast, the Conservative belief that man’s behavior is the result of an innate human nature (denied by the Left) would tend to be validated.
What we can infer now is that predominantly left-brain dominant/logical individuals are likely to see politics through a conservative lens while predominantly right-brain dominant/intuitive individuals will lean liberal/left. Conflict between the two innately held worldviews is therefore to be expected. Balance, not dominance of one or the other is optimal in the interest of responsible progress. This fits well with the more status quo worldview of passive conservatives but not as well with the “let’s rearrange the socio-economic furniture” unrest of the agenda-driven left whose social panaceas too often carry with them unforseen and deleterious side effects (e.g.; school busing). This is especially true of the Radical Left which has been discussed here in a previous essay.
Tags: Neuroscience, Politics
 Sperry, R. W. “Some Effects of Disconnecting the Cerebral Hemispheres”, 1981 Nobel lecture. Les Prix Nobel, Stockholm
 http://neuropolitics.org/defaultapr06.asp ("Left Brain, Right Brain, Whole Brain", 2007)