I have written in 2009 here about exclusion in science. It continues to be a common theme in research programs to exclude others and to be exclusive. Just recently, I found the interesting 2012 summmary on the pain of social rejection by the American Psychological Association
As clever as human beings are, we rely on social groups for survival. We evolved to live in cooperative societies, and for most of human history we depended on those groups for our lives. Like hunger or thirst, our need for acceptance emerged as a mechanism for survival
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The brain regions associated with physical pain lit up as the participants viewed photographs of their exes
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The link between physical and social pain might sound surprising, but it makes biological sense, DeWall says. “Instead of creating an entirely new system to respond to socially painful events, evolution simply co-opted the system for physical pain,” he says.
Evidence therefore accumulates since the seminal paper by Mac Donald and Leary, that exclusion really hurts, yea, yea.