Brainbabble

April 19, 2012

In this past Sunday’s Washington Post, Chris Mooney wrote, 

…at a time of unprecedented polarization in America, we need a more convincing explanation for the staggering irrationality of our politics. Especially since we’re now split not just over what we ought to do politically but also over what we consider to be true.

So true! This statement is so loaded - least of all being the implied question of what is Truth.  More on that later.

The WP opinion piece focuses on differences in personality variables between liberals & conservatives (liberals more “open to experience” and conservatives more “conscientious”). Putting aside the ethical question “who funds these studies?”, I found the scientific literature on neurophysiological differences between people of different political persuasion fascinating.  

A study out of the UK published last year suggests that anterior cingulate and right amygdala size are associated with political leanings (see Kanai et al 2011). As attitudes moved across the political spectrum from liberal to conservative anterior cingulate gray matter (neuron cell body) volume decreased and right amygdala gray matter volume increased. 

These structures are part of the traditional limbic system, are important for a number of cognitive operations, and are implicated in mood and anxiety disorders. The amygdala is important for the emotional and social evaluation of others’ faces (emotional expression, trustworthiness, attractiveness, intelligence), and has been implicated in voting choices (see Rule et al 2010). The anterior cingulate is engaged when processing pain (your own and others’), during motivated reasoning (e.g. when making judgments about information that threatens your candidate, see Westen et al 2006) and when making judgments about social dominance (e.g. whether society should be hierarchical or egalitarian, see Chiao et al 2009). 

Clearly, other brain structures are involved in processing political information.  I’m not sure why anyone would be surprised that our overall tendencies and “personality style” influences our political choices. And our preferences are probably the result of our genetics and experience, both of which influence brain structure and function.  But I do not believe we are completely bound by these constraints - this is moving into “free will” territory so I will stop here with this thread.

Remember: rational judgment is always subject to emotional bias, no matter how much we try to deny this. 

And also remember that all generalizations are wrong, including this one.