[Paleopsych] NYT: What Other People Say May Change What You See
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Tue Jun 28 18:41:40 UTC 2005
What Other People Say May Change What You See
By SANDRA BLAKESLEE
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.
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
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 their perceptions?
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
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 Biological
"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 said.
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
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 mental
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. Berns said.
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
The implications of the study's findings are huge, Dr. Berns said.
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 single person.
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 their
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