Z:gnu-www-ja-frank--1dc08b-Following a period in which su/en

Following a period in which subjects were given an opportunity to get to know one another, each subject was taken to a separate room and asked to fill out a form indicating his response (cooperate or defect) to each of the other two players in his group. After the subjects had filled out their forms, the results were tallied and the payments disbursed. Each subject received a single payment that was the sum of three separate amounts: (1) the payoff from the game with the first partner; (2) the payoff from the game with the second partner; and (3) a term that was drawn at random from a large list of positive and negative values. None of these three elements could be observed separately, only their sum.