Political neuroscientists are trying to answer a basic question – what is the relationship between political ideology and brain function? Actually this is a horrifically complex question, but we are making some incremental progress, and a recent study adds a new layer of information. But let me first back up and give some thoughts on the entire enterprise.

Obviously political ideology is a brain phenomenon, in the way that all cognitive function is a brain phenomenon. But there are interesting deeper questions. How much of political ideology is learned or absorbed from the environment, and how much is a function of our genetic neurological predisposition (nature vs nurture)? The number one predictor of political ideology is the ideology of one’s parents. But this, of course, cuts both ways – we inherit genes from our parents, but they also dominantly affect the environment of our childhood. Twin studies (looking at the political ideology of twins separated at birth) suggest that political ideology is at least partly genetic. So unsurprisingly the answer is that genetic and environmental factors are likely working together to influence political ideology.

Another layer to consider is how we define political ideology? For studies based in the US, a typical liberal vs conservative scale is used. But we have to ask – is American liberal vs conservative politics fundamental to human psychology, or is it a particular cultural manifestation that may only indirectly relate to basic cognitive function? Perhaps, in other words, we’re looking in the wrong place, where the lighting is good but not necessarily where the phenomenon is really located. All research that looks for neuroanatomic correlates suffers from this fundamental question. If we look for the neuroanatomical correlates of depression, for example, we have to ask what depression is, and if it is a foundational phenomenon or an epiphenomenon. Is it a fundamental property of neurological functioning, or just a manifestation of a deeper neurological functioning?

Therefore, is liberalism or conservatism actually a thing that directly relates to neurological functioning, or just a quirky cultural manifestation of a deeper psychological and behavioral phenomenon? If the latter, it may prove fruitless to look for neurological correlates. While we need to continue to ask this question, it does seem from prior research that liberalism and conservatism are at least meaningful concepts in terms of human cognition, even if they are not the whole story.

Also, researchers look at a related but distinct phenomenon – extremism vs moderation. Are these on the same scale or does extremism run orthogonal to ideology? In other words are extreme liberals just really liberal, or are they extremists who happen to be liberal? Should we map ideology in one dimension or two (with liberal to conservative on one axis, and moderate to extreme on another axis)? Actually I think there are likely multiple dimensions all interacting.

For the current study, however, they treat ideology as if it exists along two axes: liberal to conservative, and moderate to extremist. Operationally this means they try to correlate extremism in either direction with neurological correlates, treating extreme liberals and extreme conservatives as the same, rather than opposite ends of one dimension. I’m not sure, actually, if they looked at the data in such a way as to correlate it either way (as one or two dimensional) but the results suggest at least in part it is two dimensional.

There is a lot of preexisting research that has subjects answer a survey which places them along a spectrum from extreme conservative to extreme liberal, and then tries to correlate that ranking with neurological functioning as imaged on fMRI scan while performing specific tasks. What’s new about this study is that they are looking at functional connectivity (FC), not just anatomical structures. In other words, they are looking at the activity of circuits in the brain, not just how much one structure in the brain lights up. This is probably a better approach (but is yet another layer of complexity to this research).

They found that FC correlates very highly with political ideology, and can be as much of a predictor of ideology as the gold standard predictor – parental ideology. They looked at 9 specific tasks, including a resting state task (subjects asked to just sit and do nothing), and FC in all 9 tasks correlated with political ideology. This suggests that political ideology may be baked into some fundamental aspects of brain function, so that it may show up during any task. Either that or they happened to choose 9 tasks that all correlate with ideology (which I think is less likely). More research is needed to sort this out.

Meanwhile, there were three tasks that correlated the most.

While our analysis suggests that the empathy, reward, and retrieval tasks are the most strongly predictive of political attitude of the tasks we considered, we found that FC features from all of the tasks including resting state were correlated to political ideology, suggesting that functional signatures of political ideology persist across tasks and resting state.

The empathy task correlated with being a political moderate. This task involved looking at pictures of people expressing emotion, such as sadness or fear. Subjects with greater neurological reaction to these images tended to rank as more political moderate. The reward task, on the other hand, correlated with extremism (again, in either direction). The reward task involved subjects winning or losing money based on how quickly they pushed a button in response to a stimulus. The retrieval task involved memory retrieval, and predicted liberal to conservative ideology. The brain structures most involved in political ideology were the amygdala, hippocampus, and frontal gyrus. These suggest that political ideology is highly tied to emotion.

What does all this mean? The short answer is that we don’t know. This and other studies establish correlation only, not causation. We do not know if liberal brains cause liberal ideology or are caused by liberal ideology. We also don’t know if the tasks chosen for this study are fundamental to ideology, or incidental. This is far too complex a subject for any one study to sort out all these questions. But the data does suggest that it is a fruitful area of research.

What we may be able to conclude from this data is that ideology is at least partly, if not dominantly, an emotional rather than rational phenomenon. This fits with a lot of psychological research, which shows that we tend to form our views based on emotional instincts, and then we rationalize those views with motivated reasoning. This is perhaps why political disagreements may be so polarizing and intransigent. Reason, facts, and logic are all secondary. They are used to justify positions that we hold for deeply emotional reasons. But I do firmly believe that metacognition can get us out of this trap. It’s at least worth a try.