The implicit cognition of reciprocal exchange: automatic retrieval of positive and negative experiences with partners in a prisoner's dilemma game.

Models of reciprocity imply that cheater detection is an important prerequisite for successful social exchange. Considering the fundamental role of memory in reciprocal exchange, these theories lead to the prediction that memory for cheaters should be preferentially enhanced. Here, we examine whether information of a partner's previous behaviour in an interaction is automatically retrieved when encountering the face of a partner who previously cheated or cooperated. In two studies, participants played a sequential prisoner's dilemma game with cheaters and cooperative partners. Alternating with the game blocks, participants were asked to classify the smiling or angry facial expressions of cooperators and cheaters. Both experiments revealed congruence effects, reflecting faster identification of the smiles of cooperators (Experiments 1 and 2) and faster identification of the angry facial expressions of cheaters (Experiment 2). Our study provides evidence for the automatic retrieval of the partner's behaviour in the game, regardless of whether partners cheated or cooperated, and thus provides further evidence against the cheater detection hypothesis.