Decisions to cooperate in the Prisoner’s Dilemma may stem from ethical obligation. Alternatively, they may reflect illusory attempts to casually influence the other player’s decision. The heuristic processes would be differentially cued by the timing of the other player’s decision: Ethical obligation is less likely when the other’s decision lies inthe future; casual illusion is less likely when it lies in the past. Experiments 1 and 2 investigated this distinction in frequencies of decision patterns indicative of each heuristic across a timing manipulation. Experiment 3 contrasted prediction and postdiction probability judgments to provide further evidence for casual illusions.