ABSTRACT
At the centre of co-operative relationships is the issue of reciprocation. That is, individuals develop supportive, co-operative relationships by maintaining some awareness of give and take (i.e. equity, Brown 1986). Co-operative relationships can break down if individuals perceive others as exploiting them or if they perceive themselves as being unable to give to the relationship in an equitable way. Co-operation may recruit interpersonal modes relating to the evolution of attachment systems (e.g. liking and loving), especially since in small humanoid groups some genetic relations exist between most members. Co-operation also probably evolved because of the benefits it bestowed over hostile dominance. Finally, co-operation increases social attention holding between participants, which in turn, increases resource holding potential.
