Evolutionary origins of stigmatization: the functions of social exclusion. From the abstract: “The authors propose that phenomena currently placed under the general rubric of stigma involve a set of distinct

psychological systems designed by natural selection to solve specific problems associated with sociality. In particular, the

authors suggest that human beings possess cognitive adaptations designed to cause them to avoid poor social exchange

partners, join cooperative groups (for purposes of between-group competition and exploitation), and avoid contact with

those who are differentially likely to carry communicable pathogens.” Psychological Bulletin