The political divide between the blue and red states goes beyond geography. Partisanship appears to be rooted in the brain.
Jonas T. Kaplan, Ph.D., a psychologist at the University of California, Los Angeles, scanned 10 registered Democrats and 10 registered Republicans with functional MRI while they viewed pictures of Pres. Bush, Sen. John Kerry, and Ralph Nader during the 2004 presidential campaign (Neuropsychologia 2006; June 7, online).
Researchers found that the dorsolateral prefrontal and the anterior cingulate cortices, brain regions involved in cognitive and emotional control, worked in tandem to promote positive feelings toward the subjects' favored candidates and negative feelings toward opposing candidates.
While Democrats demonstrated negativity toward Bush and Republicans showcased similar feelings for Kerry, fMRI revealed that the Republicans could stomach Kerry more easily than the Democrats could Bush.