Perspective-Taking and Depth of Theory-of-Mind Reasoning in Sequential-Move Games

Theory-of-mind (ToM) involves modeling an individuals mental states to plan ones action and to anticipate others actions through recursive reasoning that may be myopic (with limited recursion) or predictive (with full recursion). ToM recursion was examined using a series of two-player, sequential-move matrix games with a maximum of three steps. Participants were assigned the role of Player I, controlling the initial and the last step, or of Player II, controlling the second step. Appropriate for the assigned role, participants either anticipated or planned Player IIs strategy at the second step, and then determined Player Is optimal strategy at the first step. Participants more readily used predictive reasoning as Player II (i.e., planning ones own move) than as Player I (i.e., anticipating an opponents move), although they did not differ when translating reasoning outcome about the second step to optimal action in the first step. Perspective-taking influenced likelihood of predictive reasoning, but it did not affect the rate at which participants acquired it during the experimental block. We conclude that the depth of ToM recursion (related to perspective-taking mechanisms) and rational application of beliefdesire to action (instrumental rationality) constitute separate cognitive processes in ToM reasoning.