Political persuasion is hardwired into brain

Immigration and abortion are most divisive topics, says research on how we process issues of the day

‘Political polarisation can’t be addressed on a superficial level – polarised beliefs are entrenched’

POLITICAL differences are hardwired into people’s brains, a study has found.

Those with conservative or liberal views react differently to those with opposing views on issues such as abortion or immigration, according to the Us-based study at Brown University in Providence, Rhode Island.

The brain activity of people defining themselves as politically liberal or conservative was monitored while they watched videos about culturally sensitive topics such as abortion and immigration in a 2021 experiment.

The study, led by Oriel Feldmanhall, associate professor of cognitive, linguistic and psychological sciences with the university’s Carney Institute of Brain Science, showed that the brains of participants who shared political beliefs reacted in a similar way.

Based on this research, a study out this week in the journal Science Advances looked at how people with “synchronised neural fingerprints” interpreted different words.

A group of 44 were asked to arrange words such as “abortion”, “immigration”, “American” and “police” according to their perceived similarity.

They were also asked to press a button to indicate whether the words were political or not. Participants were also shown news clips and a vice-presidential campaign debate about police brutality, during which their brain activity was measured.

Immigration was found to be the most polarising topic, closely followed by abortion, whereas policing was less polarising. People who shared political beliefs reacted in a similar way to the words, even without a political context.

Profr Feldmanhall, senior author of the newer study, said: “The reason two liberal brains are synchronising when watching a complicated video is due in part to each brain having neural fingerprints for political concepts or words that are very aligned.”

So people with different political views would interpret the same video in disparate ways and the study helped to “shed light on what happens in the brain that gives rise to political polarisation”. She said: “It’s almost like a fingerprint, a neural fingerprint that encodes the concept of that word within the brain.”

The researchers said the findings could help to develop understanding of how a controversial news channel triggers vastly different political opinions in its audience.

She concluded: “The problem of political polarisation can’t be addressed on a superficial level. These polarised beliefs are very entrenched.