A study of heartbreak and social exclusion found that the pain caused by them is the same as actual physical pain. Test subjects were engaged in a game and then shut out of it by other players, and it caused them pain that could be measured in the same way as physical pain.
Link: http://news.bbc.co.uk/2/hi/health/3178242.stm
Dr Jaak Panksepp, from the Centre for Neuroscience, Mind and Behavior at Bowling Green State University in Ohio, said that feelings of social exclusion were powerful instincts in animals and humans.
He said: "The feelings induced by experimental games in the laboratory, are a pale shadow of the real-life feelings that humans and other animals experience in response to the sudden loss of social support.
"Psychological pain in humans, especially grief and intense loneliness, may share some of the same neural pathways that elaborate physical pain."
I wonder how this relates to people on the spectrum. It seems to be a fairly universal phenomenon, and I know I have experienced what I can only describe as acute physical pain when I was bullied out of a group of friends a few years back (and it still hurts). Do you think you have experienced physical pain from being socially excluded?