Fig. 1.

Agents play PD games that are either one-shot or involve reciprocity, and either use a generalized intuitive strategy that does not depend on game type, or engage in costly deliberation and tailor their strategy based on game type. The strategy space for the agents in our model, which consists of four variables T, S_i, S₁, and S_r, is visualized here along with the sequence of events within each interaction between two agents (both agents face the same decision, so for illustrative simplicity only one agent’s decision process is shown). First, the agent’s cost of deliberation for this interaction d* is sampled uniformly from the interval [0, d]. The agent’s deliberation threshold T then determines which mode of cognitive processing is applied. If d* > T, it is too costly to deliberate in this interaction and she makes her cooperation decision based on her generalized intuitive response S_i; intuition cannot differentiate between game types, and so regardless of whether the game is one-shot (probability 1−p) or repeated (probability p), she plays the cooperative strategy with probability S_i. If d* ≤ T, however, deliberation is not too costly, so she pays the cost d* and uses deliberation to tailor her play to the type of game she is facing: If the game is one-shot, she plays the cooperative strategy with probability S₁, and if the game is repeated, she plays the cooperative strategy with probability S_r. For example, when deliberating, an agent could decide to defect in a one-shot game (S₁ = 0) but cooperate in a repeated game (S_r = 1). In contrast, when using intuition, this agent must either cooperate in both contexts (S_i = 1) or defect in both contexts (S_i = 0).