read in the paper that researchers found a neurophysiological basis for social rejection causing physical pain in the anterior cingulate cortex of the brain, the hypothesis being that the human species developed this reaction as a defense mechanism, in order to facilitate our survival by providing an impetus to remain bonded to the group. Which explains why we continue to bang our heads against the wall, seeking acceptance, even though every figurative cold shoulder literally hurts. But not as much as a punch in the face.