The neurobiology behind our place on the conservative-liberal spectrum

UCLA Health article
The neurobiology behind our place on the conservative-liberal spectrum

Americans seem more polarized than ever when it comes to their political beliefs, a division brought into sharp relief during the 2016 presidential election and its aftermath. That worries Dr. Mario Mendez, a professor in residence of neurology and psychiatry and biobehavioral sciences at UCLA; the level of discord in Congress remains the most contentious he’s ever seen.

How did we get here? Mendez wondered. To understand, he looked to the neurobiology underlying how we form our political views.

He reviewed more than 100 studies, most published since 2003, pertaining to political beliefs, from conservatism to liberalism. The studies spanned five research areas: personality differences, evolutionary and genetic information; cognitive processes, neuroimaging and brain disease. He drew from his own work as a behavioral neurologist directing the UCLA Frontotemporal Dementia Program.

Mendez observed that some of his dementia patients experienced personality changes as their disease progressed; most often, the shift was from a conservative outlook to more liberal one, supporting the idea of a neurobiological mechanism at work in determining political ideology.

His insights, published in the March 6 Journal of Neuropsychiatry and Clinical Neurosciences, shed light on how the wiring of our brains influences where we fall on the conservative-liberal spectrum. It’s also the subject of a keynote presentation on March 11 at the American Neuropsychiatric Association annual meeting in Atlanta.

“We’re all conservative and liberal in different domains,” Mendez says. “We are born prewired to form social groups, to bond, to conform, belong-- in order to work together in a collaborative society. All of these things, we think, evolved as a part of our social brain that allows humans to survive.”

On the right side of the brain, we have what Mendez calls a “conservative complex” of brain regions dedicated to maintaining stability and preservation of the status quo. It’s a self-protective, threat alarm system, consisting of the right amygdala, the right anterior insula and right prefrontal cortex. Prior studies have found these areas are more active in conservatives than in liberals; one study found the amygdala is larger in young adults with extremely conservative views.

“Political conservatives compared with liberals favor in-group conformity and out-group exclusion consistent with evolutionary behaviors for (protecting health),” Mendez writes. “Political conservatives compared with political liberals have a greater sense of threat from the same stimuli and show larger physiological responses to ambiguous stimuli.”

On the other hand, political liberals have increased activity in the anterior cingulate cortex, or ACC. Tucked inside the frontal lobe, the ACC is involved with decision making, impulse control and emotion. Prior research has shown this part of the brain prompts people to take risks, explore novel situations and try new things. In addition, the ACC monitors potential conflicts or ambiguity and prompts us not to flee or fight, but to resolve conflict and choose new actions.

Mendez notes that the wiring you’re born with doesn’t mean you won’t change over time. Knowledge, life experience and social learning have significant impact on your neurological tendencies. What’s more, both ends of the conservative-liberal spectrum offer evolutionary advantages, Mendez writes: “Conservative and liberal behavior each has advantages for individuals and society. Some situations profit more from conservatism and others from liberalism.”

The takeaway? “Political ideology divides people, societies and nations, often with serious consequences,” Mendez writes. “Elucidating the underlying sources for extreme political ideology … is important for understanding the political differences that divide us.”