This study from Emory provides an interesting view of peer pressure and the 'pain' of independence. Test subjects were given mental rotation tasks to perform individually and 'in a group'. In the group situation, they saw either the faces of others giving their answers (really student actors) or computer terminals that were supposed to be reflecting the answers of others.
When subjects succumbed to peer pressure and made errors, it was evident that they were giving in to their peers because the reaction times were shorter and they didn't activate their brains as much as when they were doing the task by themselves. The 'peer pressure' site appeared to be in the right parietal sulcus, which might be reflect the possibility of an alternative representation (from the group) being considered.
A unexpected finding was researchers were also able to see the sting of independent thinking. When people went against the group and made correct choices despite the three subjects choosing otherwise, the emotional amygdala and right caudate (salient stimuli) became activated, perhaps reflecting the pain of marching to the beat of a different drummer.
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