What Other People Say May Change What You See
What Other People Say May Change What You See
By SANDRA BLAKESLEE
Published: June 28, 2005
A new study uses advanced brain-scanning technology to cast light
on a topic that psychologists have puzzled over for more than
half a century: social conformity.
Dr. Gregory S. Berns
In the new study, subjects were asked to decide if geometric
shapes were the same or different.
The study was based on 1950's work by the psychologist Solomon
The study was based on a famous series of laboratory experiments
from the 1950's by a social psychologist, Dr. Solomon Asch.
In those early studies, the subjects were shown two cards. On the
first was a vertical line. On the second were three lines, one of
them the same length as that on the first card.
Then the subjects were asked to say which two lines were alike,
something that most 5-year-olds could answer correctly.
But Dr. Asch added a twist. Seven other people, in cahoots with
the researchers, also examined the lines and gave their answers
before the subjects did. And sometimes these confederates
intentionally gave the wrong answer.
Dr. Asch was astonished at what happened next. After thinking
hard, three out of four subjects agreed with the incorrect
answers given by the confederates at least once. And one in four
conformed 50 percent of the time.
Dr. Asch, who died in 1996, always wondered about the findings.
Did the people who gave in to group do so knowing that their
answers was wrong? Or did the social pressure actually change
The new study tried to find an answer by using functional M.R.I.
scanners that can peer into the working brain, a technology not
available to Dr. Asch.
The researchers found that social conformity showed up in the
brain as activity in regions that are entirely devoted to
perception. But independence of judgment - standing up for one's
beliefs - showed up as activity in brain areas involved in
emotion, the study found, suggesting that there is a cost for
going against the group.
"We like to think that seeing is believing," said Dr. Gregory
Berns, a psychiatrist and neuroscientist at Emory University in
Atlanta who led the study.
But the study's findings, he said, show that seeing is believing
what the group tells you to believe.
The research was published June 22 in the online edition of
"It's a very important piece of work," said Dr. Dan Ariely, a
professor of management and decision making at the Massachusetts
Institute of Technology, who was not involved in the study. "It
suggests that information from other people may color our
perception at a very deep level."
Dr. Brian Knutson, a neuroscientist at Stanford and an expert on
perception, called the study "extremely clever."
"It had all the right controls and is a new contribution, the
first to look at social conformity inside a brain magnet," he
Functional M.R.I. scanners detect which brain regions are active
when people carry out various mental tasks.
The new study involved 32 volunteers who agreed to participate in
a study on perception. "We told them others will be doing the
same task, but you're the only one who will be in the scanner,"
Dr. Berns said.
The subjects were asked to mentally rotate images of
three-dimensional objects to determine if the objects were the
same or different.
In the waiting room, the subjects met four people who they
thought were other volunteers, but who in fact were actors, ready
to fake their responses.
To encourage cohesiveness in the group, the participant and the
four actors played practice rounds on laptop computers, took
pictures of one another and chatted.
Then the participant went into the M.R.I. machine. The
participant was told that the others would look at the objects
first as a group and then decide if they were same or different.
As planned, the actors gave unanimously wrong answers in some
instances and unanimously correct answers in others.
Mixed answers were sometimes thrown in to make the test more
believable but they were not included in the analysis.
Next, the participant was shown the answer given by the others
and asked to judge the objects.
Were they the same or different?
The brain scanner captured a picture of the judgment process.
In some trials, instead of being told that the other volunteers
had given an answer, they were told that a computer had made the
decision. Dr. Berns said this was done to make sure it was social
pressure that was having an effect.
As in Dr. Asch's experiments, many of the subjects caved in to
group pressure. On average, Dr. Berns said, they went along with
the group on wrong answers 41 percent of the time.
The researchers had two hypotheses about what was happening. If
social conformity was a result of conscious decision making, they
reasoned, they should see changes in areas of the forebrain that
deal with monitoring conflicts, planning and other higher-order
But if the subjects' social conformity stemmed from changes in
perception, there should be changes in posterior brain areas
dedicated to vision and spatial perception.
In fact, the researchers found that when people went along with
the group on wrong answers, activity increased in the right
intraparietal sulcus, an area devoted to spatial awareness, Dr.
There was no activity in brain areas that make conscious
decisions, the researchers found. But the people who made
independent judgments that went against the group showed
activation in the right amygdala and right caudate nucleus -
regions associated with emotional salience.
The implications of the study's findings are huge, Dr. Berns
In many areas of society - elections, for example, or jury
trials - the accepted way to resolve conflicts between an
individual and a group is to invoke the "rule of the majority."
There is a sound reason for this: A majority represents the
collective wisdom of many people, rather than the judgment of a
But the superiority of the group can disappear when the group
exerts pressure on individuals, Dr. Berns said.
The unpleasantness of standing alone can make a majority opinion
seem more appealing than sticking to one's own beliefs.
If other people's views can actually affect how someone perceives
the external world, then truth itself is called into question.
There is no way out of this problem, Dr. Ariely said.
But if people are made aware of their vulnerability, they may be
able to avoid conforming to social pressure when it is not in