Relationship with a sociopath: breaking up is hard to do

A(nother) reason that many sociopaths like to be around people, have friends, be in relationships, etc.:

Rejection resonates with a primal threat, one the brain seems designed to highlight. [I]n human prehistory being part of a band was essential for survival; exclusion could be a death sentence, as is still true today for infant mammals in the wild. The pain center [that triggers actual physical pain at real or impending social isolation] may have evolved this sensitivity to social exclusion as an alarm signal to warn of potntial banishment--and presumably to prompt us to repair the threatened relationship.

When our need for closeness goes unmet, emotional disorders can result. . . . Social rejection--or fearing it--is one of the most common causes of anxiety. Feelings of inclusion depend not so much on having frequent social contacts or numerous relationships as on how accepted we feel, even in just a few key relationships.

Also from Social Intelligence. This interesting because I can feel severe anxiety at the prospect of a break up, resulting in nausea, headaches, and other intense physical pain. A relative of mine (also sociopath) gets the same -- always in the toilet vomiting when his girlfriend threatens to leave him. I don't know whether all socios are that way, but I imagine that they at least find isolation or abandonment to be unpleasant.