More and more I am thinking that a thorough study of irrationality would be rewarding. An interesting paper investigates peoples' tendency to be irrational about politics. A disturbing chart:

Prospects for attaining truth with different intellectual traits

   Intelligence   Bias

        +          -   (best)

        -          -

        -          +

        +          +   (worst)

So intelligence is a key factor, but the secret is in detecting bias. Do your politics favor people in your social-economic group? Is that a coincidence? If a certain out-ot-print treatise ever becomes available at a rational price I'll have to grab it.