[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
http://www.nytimes.com/2005/06/28/science/28brai.html?pagewanted=print

    By [3]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
    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 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
    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 Biological
    Psychiatry.

    "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
    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 mental
    activities.

    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
    salience.

    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
    self-interest.



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