How to change minds? A study makes the case for talking it out

WASHINGTON: Co-workers stuck on a Zoom call, deliberating a new strategy for a crucial project. Roommates at the kitchen table, arguing about how to split utility bills fairly. Neighbors at a city meeting, debating how to pay for street repairs. We’ve all been there — in a group, trying our best to get everyone on the same page. It’s arguably one of the most important and common undertakings in human societies. But reaching agreement can be excruciating. “Much of our lives seem to be in this sort of Rashomon situation — people see things in different ways and have different accounts of what’s happening,” Beau Sievers, a social neuroscientist at Dartmouth College, said.

A few years ago, Dr. Sievers devised a study to improve understanding of how exactly a group of people achieves a consensus and how their individual brains change after such discussions. The results, recently published online but not yet peer-reviewed, showed that a robust conversation that results in consensus synchronises the talkers’ brains — not only when thinking about the topic that was explicitly discussed, but related situations that were not. The study also revealed at least one factor that makes it harder to reach accord: a group member whose strident opinions drown out everyone else.

“Conversation is our greatest tool to align minds,” said Thalia Wheatley, a social neuroscientist at Dartmouth College who advises Dr. Sievers. “We don’t think in a vacuum, but with other people.”

Dr. Sievers designed the experiment around watching movies because he wanted to create a realistic situation in which participants could show fast and meaningful changes in their opinions. But he said it was surprisingly difficult to find films with scenes that could be viewed in different ways. “Directors of movies are very good at constraining the kinds of interpretations that you might have,” he said.

Groups of volunteers came up with different interpretations of the same movie clip. Despite having watched the same clips, the brain patterns from one group to another were meaningfully different, but within each group, the activity was far more synchronised.

The results have been submitted for publication in a scientific journal and are under review.

“This is a bold and innovative study,” said Yuan Chang Leong, a cognitive neuroscientist at University of Chicago who was not involved in the work.

The results jibe with previous research showing people who share beliefs tend to share brain responses. For example, a 2017 study presented volunteers with one of two opposite interpretations of “Pretty Mouth and Green My Eyes,” a short story by J.D. Salinger. The participants that had received the same interpretation had more aligned brain activity when listening to the story in the brain scanner.

And in 2020, Dr. Leong’s team reported that when watching news footage, brain activity in conservatives looked more like that in other conservatives than that in liberals, and vice versa. The new study “suggests that the degree of similarity in brain responses depends not only on people’s inherent predispositions, but also the common ground created by having a conversation,” Dr. Leong said.

The experiment also underscored a dynamic familiar to anyone who has been steamrollered in a work meeting: An individual’s behavior can drastically influence a group decision. Some of the volunteers tried to persuade their groupmates of a cinematic interpretation with bluster, by barking orders and talking over their peers. But others — particularly those who were central players in the students’ real-life social networks — acted as mediators, reading the room and trying to find common ground.