Here's a PDF of the article itself.
A psychiatrist at NYU, David Amodio, studies how behaviours show up in brain scans. He has shown that self-identified liberals and conservatives not only react differently in the same situations, but that their brains give off different signals in those situations. Here is a biography of Dr. Amodio, and here is a list of responses to the article.
I'm fascinated - I want to know how the mechanism is passed on to kids (the very first link suggests that it might be hereditary). Is it genetic? Or is it nurtured? As I watch my own child grow up, I wonder how he learns some things such as experimentation and decision-making. Obviously he learns some habits and methods from watching us, and from having us guide him to make good choices, but are those habits and methods reinforcing what's already there? Or are they shaping an entirely arbitrary and unformed anterior cingulate cortex that we as parents are nurturing just by being around the child and demonstrating our own political tendencies? There are plenty of anecdotal stories about liberal 'black sheep' in conservative families and vice versa. Does this mean that a tendency toward liberalism or conservatism is hard-wired? This is completely fascinating to me.