Baumeister and Leary (1995) argue compellingly that human beings have a need to belong, and that this need may be deeply rooted in the experience of homo sapiens in their Environment of Evolutionary Adaptedness (EEA). For humans, the Environment of Evolutionary Adaptedness is commonly taken to be the Pleistocene environment in which the overwhelming majority of human evolution is thought to have occurred. The need to belong to a group may, however, be only the most basic of the adaptations that emerged during the EEA for humans. It seems likely that a variety of other social adaptations have developed as well, and that these serve to further the goal of maintaining or optimizing group involvement and pair bonding.
Leary and Downs (1995) note, for example, that evaluative feelings about the self may serve as a social adaptation “that (1) monitors the social environment for cues indicating disapproval, rejection, or exclusion and (2) alerts the individual via negative affective reactions when such cues are detected.” (Leary & Downs, 1995, p. 129). Gilbert (1992) also hypothesizes that mechanisms to enhance smooth functioning within a group or dyadic context may have assumed increasing evolutionary importance as homo sapiens became more oriented to alliances and sharing. Gilbert (1992) highlights the emergence of strategies to gain and control others' attention through coalitions and cooperative activity, rather than exclusive reliance on strategies to attain dominance via threat and aggression.