respondents who had described themselves as liberals showed "significantly greater conflict-related neural activity" when the hypothetical situation called for an unscheduled break in routine.

Conservatives, however, were less flexible, refusing to deviate from old habits "despite signals that this ... should be changed."

Whether that is good or bad, of course, depends on one's perspective: one could interpret the results to mean that liberals are nimble-minded and conservatives rigid and stubborn.

Or one could, with equal justice, conclude that wishy-washy liberals don't stick to their guns, while conservatives and steadfast and loyal.

As to the more intriguing question of which comes first, the patterns in neuron activity or the political orientation, Amodio is reluctant to hazard a guess.

"The neural mechanisms for conflict monitoring are formed early in childhood," and are probably rooted in part in our genetic heritage, he said.

"But even if genes may provide a blueprint for more liberal or conservative orientations, they are shaped substantially by one's environment over the course of development," he added.

Obscuring causal links even more is the fact that the brain is malleable and neural functions can change as a result of new experiences.