There’s a growing body of evidence demonstrating the difference in brain structure between liberals and conservatives (which just might explain why each side thinks the other is brain damaged).
Conservatives tend to have a larger and more active right amygdala , a part of the brain associated with fear, for lack of a better word. This isn’t to say conservatives are cowardly. Instead, it manifests as more active fight-or-flight responses or a focus on preventing negative outcomes rather than working toward positive goals . Conservatives learn better from negative stimuli and are more risk avoidant than liberals .
Liberals’ brains tend to have a greater volume of the anterior cingulate cortex . The ACC appears to monitor conflicting information and allow one to tolerate uncertainty. While they’re more open to new experiences than conservatives, they’re also less orderly .
Remember- this is not an either/or thing. Conservatives can be open to new things and liberals have fight/flight responses. This is simply physiological explanation of one’s tendency toward a behavior.
What I found really interesting in the video below was considering the brain’s plasticity- it makes the political tendencies and the brain structure a chicken & egg question. Brain structure is a more accurate predictor of political affiliation than even the affiliation of one’s parents. So do we think the way we do because of our physiology? How much does our brain structure change from our thoughts/experience? To what degree can a person really change their ideology? It’s a great example of remembering that correlation is not causation.
I think back to when I taught concealed carry in Arizona and carried a pistol with me everywhere, despite never having been violently accosted. While I still think firearms are cool, I quit worrying about worst-case scenarios because they’re so exceedingly rare that they’re statistically implausible. But back then, confirmation bias had me poring over case studies of violent self-defense to the point it seemed to be everywhere. I’m guessing my right amygdala was pretty healthy.
This also explains the politics of fear we see today, specifically the completely untrue statements of Donald Trump being taken seriously. “Make America Great Again” implies that this isn’t currently a great nation- which is a completely subjective value statement but faces me to ask what people really think is so wrong. How have Trump supporters actually been harmed? The fear-mongering about illegal immigrants flies in the face of reality- that population has been on the decline since 2007 . Saying we “lose” in trade deals with China is another false, fear-based bit of rhetoric based in ignorance- Alibaba went public on the New York Stock Exchange (not a Chinese exchange, or Dubai, or European) because America is the financial hegemon of the world. The jobs farmed out to China are low-tech, low-skill menial labor; we have them make our stuff because we’re too wealthy and educated to those jobs anymore.
But fear-mongering is effective. It’s handed Trump the GOP nomination without a whit of fact to his claims. It’s led to a fight over public bathrooms in North Carolina, despite that fact that no transgender people have ever been arrested for sexual misconduct in a bathroom, but three Republican lawmakers have . I’ve already placed my bet that news ratings have more to do with sensationalism than anything, but let’s expand on that topic.: The only thing that outsells fear is sex, which is why women on cable news all show their legs while discussing the next big threat to America. Ratings double whammy.
The problem with fear-based thinking is that it’s Type 1, which means it’s not rigorously analyzed. Fear-based reasoning is rarely sound, but there is a sound reason it happens.
Kanai, Ryota, Tom Feilden, Colin Firth, and Geraint Rees. “Political orientations are correlated with brain structure in young adults.” Current biology 21, no. 8 (2011): 677-680.
 Janoff-Bulman, Ronnie. “To provide or protect: Motivational bases of political liberalism and conservatism.” Psychological Inquiry 20, no. 2-3 (2009): 120-128.
 Shook, Natalie J., and Russell H. Fazio. “Political ideology, exploration of novel stimuli, and attitude formation.” Journal of Experimental Social Psychology 45, no. 4 (2009): 995-998.
 Carney, Dana R., John T. Jost, Samuel D. Gosling, and Jeff Potter. “The secret lives of liberals and conservatives: Personality profiles, interaction styles, and the things they leave behind.” Political Psychology 29, no. 6 (2008): 807-840.
 U.S. Senator Larry Craig, FL state Rep Bob Allen, MS Congressman Jon Hinson.