Political opinions come from the heart, but the head claims the credit.

Our certitude and vehemence in political argument are way out of proportion to our knowledge...In politics, everybody is always very sure that they are right. But they simply can't be. When the Democrats and Republicans take opposed positions, they can't both be right. Thus, on any critical policy debate, about half the electorate and politicians are completely wrong, yet are blithely and majestically assured that they are right.

Our political opinions emanate from deep cultural and biological sources...This explains why we get so emotional about politics and why political compromise is generally impossible. When someone criticizes our politics, they attack our very being. Political debate is futile because it is based on the naive premise that we can be convinced by the logical arguments of our enemies to change our inner selves.

Humans can intuitively sense through a variety of subtle clues (i.e., dress, accent, gestures) when another person possesses a mix of cultural and psychological characteristics that is so substantially different to our own that political discord is also likely. Put otherwise, a liberal can usually smell a conservative, and vice versa. Moreover, the smell is not a pleasant one.-- Red Genes, Blue Genes: Exposing Political Irrationality