Yi, R. & Rachlin, H. (2004).
Contingencies of reinforcement in a five-person prisoner’s dilemma.
Journal of the Experimental Analysis of Behavior, 82, 161-176.
As in studies of self-control, a tit-for-tat contingency in an iterated prisoner’s
dilemma game creates a conflict between maximization of local and global reinforcement.
The present experiments examine this conflict in a multiplayer prisoner’s dilemma game.
Versus tit for tat, cooperation corresponds to self-control; defection, always
immediately reinforced, corresponds to impulsiveness. Three experiments examined
sensitivity of behavior to the global reinforcement contingency imposed by
tit for tat. Undergraduates played a five-player prisoner’s dilemma game
against four dummy players programmed to play tit for tat or randomly.
With tit for tat, a player’s cooperation (or defection) increased dummy
players’ cooperation (or defection) on subsequent trials-reinforcing
cooperation and punishing defection in the long run. Participants
cooperated at a higher rate when the dummy players played tit for
tat than when the dummy players played randomly. These results are
consistent with findings in corresponding studies of self-control.
Some participants, caught in a trap of mutual defection with the
tit-for-tat playing dummy players, came to cooperate when the
tit-for-tat contingency was reset (“forgiving” participants’
previous defections) during a pause in the game. This increase was a
result of the combined effects of a pause and reset; neither pausing
nor resetting independently resulted in an increase in cooperation.
Key words: prisoner’s dilemma, self-control, reinforcement, tit for tat, choice, humans