In the wake of World War II, stunned by the German peoples adoption of Hitler's horrific vision of Aryan purity, psychologists set out to discover the mechanisms of social control. One of the most famous studies to emerge during this period was conducted by Gestalt Therapist Solomon Asch. In the early 1950s, Asch designed a series of studies, which became known as the Asch Conformity Experiments.
Asch recruited a group of students to participate in what he called a "vision test." Each participant was seated in a classroom filled with what he presumed to be fellow test subjects. In reality, the "peer group" was made up of Asch conspirators. The test subject was then presented with two cards. Card 1 had a line on it. Card 2 contained three lines of varying lengths, marked a, b, and c. The test subject was then asked to identify which line on Card 2 was the same length as the line on Card 1.
Left to their own devices, the test subjects invariably picked line "c." But when the peer group insisted on a different answer, the guinea pigs frequently fell in line. For instance, if Asch conspirators claimed that line "b" was the correct answer, 33 percent of the test subjects concurred.
In the face of intense social pressure, many of Asch's subjects denied the truth staring them in the face.
Since the 1950s, psychologists have wondered what was going on in the brains of Asch's volunteers. Were they simply lying in order to reduce their discomfort? Or was it possible that their perceptions altered in response to group pressure?
Most of us would assume that the subjects were lying. We can plainly see that line "c" on Card 2 corresponds with the line on Card 1. But as it turns out, our view of reality is more susceptible to suggestion than previously supposed.
In June 2005, psychiatrist Gregory Berns of Emory University published a study that picked up where Ash's left off. And his results are startling. The key difference in this study was that Berns' subjects were placed in an MRI machine, which tracked activity in their brains while they underwent the test.
Before taking the test, each subject was ushered into a waiting room where he met four other "volunteers." These volunteers were, of course, plants--actors who had been instructed to give incorrect responses. To promote a feeling of solidarity, the subject and fellow "volunteers" were left alone in the room to talk, practice for the test, and take pictures of one another. Once they'd developed a rapport, the test commenced.
The real volunteer was put into an MRI machine and asked to "mentally rotate images of three-dimensional objects to determine if the objects were the same or different." (What Other People Say) The four actors were also in the room.
The rest of the test followed a similar model to Ash's. When asked to correctly identify similar shapes, the four actors gave the wrong answer. Berns' test subjects parroted the actors' incorrect answers 41 percent of the time.
If the subjects were flat out lying, Berns reasoned, the MRI would reveal activity in the forebrain, the area associated with conscious deception. (Forebrain) But that's not what showed up on the scan. The test subjects that concurred with the group showed changes in the posterior brain, the part responsible for visual 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 . . . There was no activity in brain areas that make conscious decisions, the researchers found.
The subjects weren't lying at all. The MRI scans reveal that those who capitulated to the group actually experienced a shift in perception. If the group insisted that a shape was square, suggestible subjects literally "saw" a square.
These findings may not surprise those of you who've read You are getting very sleepy. You already know how malleable the human mind is. What I found really intriguing about Berns' study was the contrarians.
The subjects who stuck to their guns, insisting that the square was indeed a square despite group pressure, "showed activation in the right amygdala and right caudate nucleus--regions associated with emotional salience." Put simply, the holdouts continued to employ logic in the face of intense pressure.
Berns' MRI scans have answered the questions introduced by Asch's study fifty odd years ago. But they haven't solved the real riddle. Why is it that some people are so susceptible to social pressure, while others are capable of resisting? The real breakthrough will come when we know what biological or social factors enable people to stand apart from the group.