Conforming Opinions Activate the Brain’s Reward Center


by Kayt Sukel

November 2, 2010

Yesterday, I passed a teenager wearing a t-shirt emblazoned with the words, “Reject Conformity.” Conformity gets a bit of a bad rap these days—often, there seems to be more emphasis placed on being individuals, rebuffing peer pressure and challenging the status quo. But new research examining the neural correlates of social influence suggests that conforming behaviors may be a more innate process than previously imagined.

Underestimating the effect

Vasily Klucharev, a researcher in the department of economic psychology at Basel University in Switzerland, studies the brain mechanisms of social influence and how they can alter our behaviors.

“Social influence affects quite a bit of our behavior. Most of the time, we really underestimate the influence of conformity,” he says. “We don’t realize our behaviors are determined by others. More interestingly, studies show it’s usually the last reason we’ll give to explain a behavior.”

Klucharev and colleagues used functional magnetic resonance imaging (fMRI) to scan the brains of individuals rating the attractiveness of faces. After ratings, participants were informed of the average rating for each face and then asked to rate again. The group found that the majority of study participants changed their opinion in line with the majority. And when they did so, the rostral cingulate zone and the ventral striatum, a brain circuit implicated in reinforcement learning, was activated.

“When you see a difference between your own opinion and that of others, the brain experiences an error signal,” says Klucharev. “And when we detect that kind of error signal, it’s a signal to learn and adjust your behavior.” They published the results in the Jan. 15, 2009, issue of Neuron. 

Rewarding conformity

But the brain may be doing more than just adjusting error when an individual is faced with others’ opinions—it may be actively rewarding conformity.

Chris Frith and Daniel Campbell-Meiklejohn, two members of the Interacting Minds Project at Aarhus University in Denmark and University College London, also found ventral striatum activation in a task rating pop songs. In the study published in the June 17, 2010, issue of Current Biology, the two researchers then demonstrated that the reward centers of the brain were activated when a participant’s rating matched that of two experts.

“Everyone has an opinion on pop music,” says Frith. “And we found that activity in the ventral striatum was very high when the individuals and the experts agreed on a song.”

Their finding suggests that others’ opinions, when shared with your own, are rewarding. “That shared opinion is a reward like food or money,” says Campbell- Meiklejohn. “And it has the power to influence behavior.”

Predicting behavior based on conformity

In both studies, the researchers could see patterns of ventral striatum activity and use them to predict successfully which individuals would adjust their ratings to fall in line with the status quo.

“It looks like a very automatic process,” says Klucharev, “something that happens whether we’re aware of it or not.” This, he suggests, may explain why we don’t realize changes in our behavior are influenced by what our peers are doing.

Klucharev also suggests that these two studies are just two angles of the same story. “When you make an error, you have to change. My theory emphasizes errors,” he says. “But if you look at it in the opposite way, that when you agree with other people you are rewarded by the group, this kind of sustained behavior also reinforces.”

All three researchers caution that these studies are only a first look into the neural correlates of social influence. There’s still much to learn.

“There are so many variables that can impact social influence,” says Frith. “We don’t know why some conform and why some rebel —and under which circumstances. There are still so many questions to ask. What we see now is that it’s very rapid learning, a very basic and quick process. And it’s one that can have quite an effect on our behaviors.”