Research on the biology of political beliefs provides insight into the effectiveness of canvassing (or really, how to win any argument). Current theories suggest that people’s political beliefs are driven by their identification with a group—similar to sports team loyalties, but more rooted in values, which makes them harder to change. Processing political thoughts may be a simple question of "Us versus Them."
Onscreen: Political messaging is everywhere. Inside this storm of ideas, what’s happening to your brain?
Emile Bruneau: We have too much information coming into our brains to process it all slowly and carefully. So our brain uses all sorts of shortcuts so that information can be processed really quickly.
Onscreen: To understand these shortcuts, scientists have used fMRI (a type of brain scan) to see which parts of the brain light up when we think about politics.
Jay Van Bavel: It gives us a clue about whether it’s driven by emotion, reason, social cognition or some other thought process.
Onscreen: It turns out thinking about politics taps into our brains’ tendency to rely on group identity, something rooted in prehistoric times.
Mina Cikara: We’re group organisms for a good reason. Our ancestors who were able to identify and cooperate with fellow group members reaped numerous benefits.
Onscreen: Early humans formed groups for protection.
Van Bavel: Humans are pretty flimsy creatures, and throughout evolutionary history, we wouldn’t have survived on our own.
Onscreen: Times may have changed, but group identity remains essential to how we think about the world.
In one fMRI study, researchers divided subjects randomly into two teams and asked them about each other. Even though before the experiment they were all strangers, subjects were more positive about their teammates than rivals and had distinct patterns of brain activity, depending on whether asked about a teammate or a foe. Including in the anterior cingulate cortex and the insula.
These regions respond to both rewards and threats in the environment, helping us differentiate friend versus foe, telling us who to approach (our team) and who to avoid (the other team). The same brain patterns appeared when subjects thought about the political group identities of others.
Cikara: Acting as a member of a group leads you to adopt different priorities and motivations.
Onscreen: So can we ever overcome group identity to change someone’s mind?
In another fMRI study, when participants were confronted with an opposing political opinion, some had increased activity in the amygdala, a part of the brain that processes emotion and fear. These individuals were less likely to change their minds. But one way to overcome the amygdala’s influence may be logic.
Bruneau: Threat is something really important to humans. If you feel threatened, you’re much less able to reason and listen. But if you keep people from feeling threatened and emotional, you allow them to dwell in that part of their brain that’s involved in reasoning, that’s necessary to change your mind.
Aparna Nathan and Robin Kazmier
© WGBH Educational Foundation 2018