There are several new books out that attempt to analyze politicaldifferences in terms of variations in neurological structure. The one being most widelyembraced by the left is The Republican Brain by Chris Mooney. Here’s how Alternet’s Joshua Holland introduced readers at Salon to the topic:

Considerfor a moment just how terrifying it must be to live life as a truebeliever on the right. Reality is scary enough, but the alternativereality inhabited by people who watch Glenn Beck, listen to RushLimbaugh, or think Michele Bachmann isn’t a joke must be nothing lessthan horrifying.

And this terrifying existence is the result of a specific part of the brain called the amygdala:

Researchsuggests that conservatives are, on average, more susceptible to fearthan those who identify themselves as liberals. Looking at MRIs of alarge sample of young adults last year, researchers at UniversityCollege London discovered that “greater conservatism was associated withincreased volume of the right amygdala” ($$). The amygdala is anancient brain structure that’s activated during states of fear andanxiety.

Liberal descriptions of the amygdalainvariably describe it as ancient or primitive. They don’t come rightout and say it but the suggestion is that the amygdala is sort of likethe human appendix which occasionally becomes inflamed and results in appendicitis. It’s aholdover, a vestigial brain function which we modern, civilized peoplewould be better off without. Here’s Mooney’s description of the role ofthe amygdala:

In a recent interview, Chris Mooney,author of “The Republican Brain,”explained, “The amygdala plays the samerole in every species that has an amygdala. It basically takes over tosave your life. It does other things too, but in a situation of threat,you cease to process information rationally and you’re movingautomatically to protect yourself.”

Mooney’sdescription once again reinforces the idea that the amygdala isprimitive and only of use in situations where panic would cloud rationalthought. In fact, the amygdala mediates memory, facilitates emotional learningand apparently helps people identify the emotional states of others.There is even research suggesting amygdala size correlates with the sizeof a person’s social network,i.e. how many friends you have.

But what’s really missing from Mooney’sdescription is any sense that the amygdala is an important part of thehuman personality, one we definitely don’t want to live without.Because, as it turns out, there’s plenty of credible scientific research which suggests thathaving a shrunken or damaged amygdala may be what makes some peoplepsychopaths. Yes, I said psychopaths, as in people without fear orconscience.

In a 2009 study of 27 psychopaths, researchers foundthe psychopaths showing a thinning of the outer layer of that regioncalled the cortex and, on average, an 18-percent volume reduction inthis part of brain.” A more recent study of Wisconsin prison inmates foundthe front of the brain called the ventromedial prefrontal cortex, orvmPFC, and the amygdala.”

This 2003 editorial in the BritishJournal of Psychiatry discusses how a damaged amygdala might lead to apsychopathic personality:

The amygdala is involved in aversive conditioning and instrumental learning ( LeDoux, 1998). It is also involved in the response to fearful and sad facial expressions ( Blair et al, 1999).The amygdala is thus involved in all the processes that, when impaired,give rise to the functional impairments shown by individuals withpsychopathy. It is therefore suggested that amygdala dysfunction is oneof the core neural systems implicated in the pathology of psychopathy ( Patrick, 1994; Blair et al, 1999).

Thepoint here is not to suggest that progressives are psychopaths. That’s acheap shot that a) is easily discounted and b) plays right into thepsychopundit’s views of conservatives as fear-mongers. I’m not suggesting conservativesshould be afraid of data about neurological variation. The real point issimply that there are psychic, social and political advantages and disadvantages which can be associated with both sides of this amygdala-continuum.

Forinstance, Mooney and others point to liberal’s openness to newexperience, as one of their great psychological strengths. In this Huffington Post video,Mooney talks about this quality over an image of a man bungee jumpingoff a cliff. But this kind of risk taking is part of a continuum. Underthe center-left end of the openness bell curve may sit things like trying exoticnew foods and, a bit further out, bungee jumping. That kind of opennessis certainly admirable and fun. But that tendencyis not without its downsides.

Monkeys who’ve had lesions to theiramygdala will play with snakes. Like psychopaths, their fearlessnessmeans they may put themselves in real danger. In the case of humans,indiscriminate openness to new experiences might include a willingnessto experimentwith crystal meth or heroine or crack. Unlike trying new foods, there’sreal (as opposed to imagined) danger involved with doing these things.And, again, theextreme left end of the “openness” continuum may be a person who actscompletely without fear of consequences to himself or others, i.e. apsychopath.

If we emulate Mooney’s trick of politicizing ourvariability we might say that progressives, whose entire politicalidentity is about leaning forward, sometimes display aconspicuous inattention to real (as opposed to imagined) dangers. Forinstance, maintaining a $15 trillion debt and planning to add $7trillion more over the next decade is not something that most economistsconsider a good idea. Like playing with a snake, there is a real dangerthat this could lead to a further downgrade of our credit or even a runon banks (as has begun to happen in Greece). We don’t need to be in apanic over these things, but it’s rational to point out that there isreal risk involved in choosing to not deal with these problems.

If having a larger amygdala correlates withconservatism, so be it. It’s both ironic and understandable that theleft would see mostly the social and political dangers of this. But it’salso likely that having a smaller amygdala can be associated with its own social andpolitical disadvantages. And certainly a world without amygdalas is not one thatanyone but a psychopath would want to live in.