Pruitt and Kimmel (1976) examined the extensive literature on the Prisoner's Dilemma game, and concluded that one important consideration for subjects is whether or not they view the interchange from a short-term or long-term perspective. In particular, if subjects believed that they would need to interact with each other after the study was concluded, and therefore the usual social and temporal isolation of such interactions was removed, their behaviour became considerably more cooperative.

XREF: Connects to Axelrod's work on the iterated Prisoner's Dilemma and the shadow of the future — repeated interactions sustain cooperation even among rational actors. Builds on: "Cooperation among strangers requires time and repeated future interaction."

Diego Gambetta, Trust - Making and Breaking…, loc. 554