To find out more about the underlying motivations of human punishment, the team devised an experiment to see whether human punishment is triggered by a desire to reciprocate losses or by an aversion to unequal outcomes. Subjects were assigned one of two roles, and then allocated money according to one of three different treatments. The team found that humans are sensitive to inequity but not to losses when deciding whether to punish a cheating partner.
MORE: http://www.sciencedaily.com/releases/2012/07/120718074035.htm
