Political Neuroscience: The Difference Between The Conservative And Liberal American Brain


We all followed the American presidential debate this year between a conservative president and a liberal former vice-president. We as a world have witnessed the ever-growing divide between those who support the major conservative party (the Republicans) and those who support the major liberal party (the Democrats). A field of neuroscience – political neuroscience – studies individual human behaviour and decision making in regard to political behaviour using neuroimaging methods. Studies within this field have shown that the differences between those who are conservative and liberal not only stems from individual variability but also has a biological root.

Previous political neuroscience research has shown that, when comparing conservative and liberal brains, specific areas vary in size. Conservatives tend to have a larger amygdala (which plays an important role in emotions and fear processing), as conservative individuals deem security and predictability important. Liberals on the other hand have a larger volume of grey matter in the anterior cingulate cortex (ACC) (which plays a role in cognitive functions such as decision-making and performance monitoring by detecting errors). However, these studies are probabilities due to our individual differences which, result in variation within our decision making irrespective of our politically assigned label. Therefore, political neuroscience has advanced to the role our cognitive processes play in our political ideologies.

Hass et al (2017) conducted a study using hypothetical political candidates from both major parties, showing how our cognitive processes play a role in our political ideology. They examined the effect of neurological functions of individuals who identified as liberal or conservative on whether or not a position (expected or unexpected) held by a party candidate was good or bad. This study revealed that liberal candidates had a higher probability of the activation of the ACC and insula (which plays a role in our social emotions) when an unexpected position came from a party candidate – especially from a democratic candidate. Additionally, those who identified as liberal in comparison to their conservative participants were more likely to base their decision on whether or not the position presented by the liberal candidate was expected or unexpected. They were also more likely to rate the expected position as good and unexpected as bad. It is important to remember that the candidates used were hypothetical and real-life politicians are much more complicated than this control.

FMRI showing the activation of the ACC and insula within the liberal brain. a.) The ACC b.) The insula. These areas of the brain are activated when unexpected positions are held by candidates, especially from the same party.
Congruent: Expected positions of candidates.
Incongruent: Unexpected positions of candidates.
Ingroup: Same party candidate
Outgroup: Opposing party candidate.
Source: Hass et al. Who Can Deviate from the Party Line? Political Ideology Moderates Evaluation of Incongruent Policy Positions in Insula and Anterior Cingulate Cortex.

Hass has suggested that motivational reasoning (an unconscious tendency of individuals to justify particular decisions irrespective of opposing evidence), may play a role in the restrained responses to unexpected positions same party candidates of the participants may hold. Political neuroscientist Hannah Nam has suggested that this may lead to system justification (the acceptance of societal inequalities promoted by party candidates). Two independent studies in regard to how likely individuals are to protest or accept social inequalities promoted or permitted by same party candidates, allowed Nam et al to suggest that the amygdala correlates to the protest or acceptance of social inequalities. The larger volume of the amygdala lowers the protest of social inequalities promoted by same party candidates in both men and women. This clearly demonstrates that our cognitive processes do play a role in our political ideologies. Therefore, more research is required to further determine how other processes impact our political ideologies. It may also provide a window of opportunity for intervention to reduce animosity and possibly mend the relationship between these opposing partisans.

The field of political neuroscience allows us to gain an understanding into the biological reasoning behind the widening divide between liberals and conservatives. It also allows the opportunity for intervention which could lessen the divide between these opposing partisans and unify a divided nation.

I urge you to read the article which inspired this one (linked below) and the papers included in this article as well as some additional resources related to political neuroscience (also linked below). I am sure it will provide a scientific light into the divide between conservatives and liberals.

Edited by Cyrus Rohani-Shukla

Original source: https://www.scientificamerican.com/article/conservative-and-liberal-brains-might-have-some-real-differences/?amp=true

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