I asked the audience to imagine that I was running a game show. I announced that I would go along every row, starting at the front, and give each member a chance to say “cooperate” or “defect.” Each time someone said “defect” I would award a euro only to her. Each time someone said “cooperate” I would award ten cents to her and to everyone else in the audience. And I asked that they play this game solely to maximize their individual total score, without worrying about friendship, politeness, the common good, etc. I said that I would stop at an unpredictable point after at least twenty players had played

Like successive motivational states within a person, each successive player had a direct interest in the behavior of each subsequent player; and had to guess her future choices somewhat by noticing the choices already made. If she realized that her move would be the most salient of these choices right after she made it, she had an incentive to forego a sure euro, but only if she thought that this choice would be both necessary and sufficient to make later players do likewise.

In this kind of game, knowing the other players’ thoughts and characters– whether they are greedy, or devious, for instance—will not help you choose, as long as you believe them to be playing to maximize their monetary gains. This is so because the main determinant of their choices will be the pattern of previous members’ play at the moment of these choices. Retaliation for a defection will not occur punitively– a current player has no reason to reward or punish a player who will not play again — but what amounts to retaliation will happen through the effect of this defection on subsequent players’ estimations of their prospects and their consequent choices. These would seem to be the same considerations that bear on successive motivational states within a person, except that in this interpersonal game the reward for future cooperations is flat (ten cents per cooperation, discounted negligibly), rather than discounted in a hyperbolic curve depending on each reward’s delay.

Perceiving each choice as a test case for the climate of cooperation turns the activity into a positive feedback system—cooperations make further cooperations more likely, and defections make defections more likely. The continuous curve of motivation is broken into dichotomies, resolutions that either succeed or fail.

George Ainslie, A Selectionist Model of the Ego: Implications for Self-Control (also see pp93-94 in Breakdown of will)