On Peer Pressure and Brain Scans

This week’s learning is from Quiet by Susan Cain and is part of a series on “Brainstorming and Peer Pressure”. (Part 1, 2, 3)

In 2005, Gregory Burns decided to conduct an updated version of the original experiments on peer pressure. In the “alone” case, 32 volunteers (men and women between 19-41 years) were subjected to various vision tests. They got 86.2% of the answers correct.

In the “group” case, they were asked to answer these questions with planted actors who confidently gave wrong answers. Here, they only got 59% correct.

The interesting addition was FMRI scans of their brains. These results were both disturbing and illuminating –

Alone Case: The scans showed activity in the Occipital (visual) cortex, parietal cortex and some activity in the pre-frontal cortex when they made the conscious decision to answer the question. All normal.

Group Case: The area of interest here was the pre-frontal cortex. If participants KNEW they were wrong but went with peer pressure, then activity was expected in the pre-frontal cortex as they would be actively deciding against the right answer. But, if the activity was in the visual, spatial area, it meant that the group had managed to somehow change the way they “perceived” the same images.
And, that’s exactly what happened..

Thus, peer pressure was shown to change the participant’s view of a situation. Groups are like mind altering substances. If the group believes the answer is A, you genuinely believe the answer is A.


Sketch by EB

Luckily, this was not always the case. Sometimes, individuals did pick the right answers. Here, the researchers observed activity in the amygdala, a small organ associated with upsetting emotions like the fear of rejection. Burns called it the pain of independence. And, these pains are critical to the survival of order in our society since our systems – elections, democracy, etc., depend on dissenting voices to drive change.

Here’s to ensuring we watch out for peer pressure effects during team meetings this week!