Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
In an experiment, players? ability to learn to cooperate in the repeated prisoner?s dilemma was substantially diminished when the payoffs were noisy, even though players could monitor one another?s past actions perfectly. In contrast, in one-time play against a succession of opponents, noisy payoffs increased cooperation, by slowing the rate at which cooperation decays. These observations are consistent with the robust observation from the psychology literature that partial reinforcement (adding randomness to the link between an action and its consequences while holding expected payoffs constant) slows learning. This effect is magnified in the