Neuroimaging studies show the PFC reining in more emotional brain regions in the name of doing (or thinking) the right thing. Stick a volunteer in a brain scanner and flash up pictures of faces. And in a depressing, well-replicated finding, flash up the face of someone of another race and in about 75 percent of subjects, there is activation of the amygdala, the brain region central to fear, anxiety, and aggression.[*] In under a tenth of a second.[*] And then the PFC does the harder thing. In most of those subjects, a few seconds after the amygdala activates, the PFC kicks in, turning off the
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