Political Leanings May Show in Brain

Sept. 10, 2007 -- Liberals and conservatives may handle mental conflict differently, according to new research on the brain.

The finding comes from researchers including David Amodio, PhD, a research scientist in New York University's psychology department. They scanned the brains of 43 adults during a conflict test.

As part of a confidential personality survey, participants rated their political orientation on a scale ranging from -5 (for extremely liberal) to +5 (for extremely conservative).

After finishing the survey, they donned stretchy caps studded with electrodes to scan their brains during the conflict test.

The test had nothing to do with candidates, votes, or prickly political issues.

Participants watched a computer screen that displayed the letter "M" or "W" for a split second in rapid succession.

The researchers asked half of the group to press a computer key whenever they saw "M" but not "W." The other half of the group got the opposite assignment -- press the button for "W" but not "M."

Most of the time, participants saw the letter that was supposed to prompt them to press the computer key. But 20% of the time, they saw the other letter and were supposed to refrain from pushing the computer key.

Compared with conservatives, liberals were more likely to refrain from pressing the computer key when the wrong letter appeared. Liberals also showed more activity in a brain area called the anterior cingulate cortex, which is involved in monitoring conflicting information, note Amodio and colleagues.

"Although a liberal orientation was associated with better performance on the response-inhibition task examined here, conservatives would presumably perform better on tasks in which a more fixed response style is optimal," write the researchers.

The study appears in the advance online edition of the journal Nature Neuroscience.

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