"I" Always Cooperate: Self-Positivity Bias in Destination Memory for Cooperation and Cheating

A growing body of research on episodic memory in interpersonal interaction divides it into two subtypes: source memory (i.e., memory for the match between inputted information and its sources) and destination memory (i.e., memory for the association between outputted information and its destinations). A topic related to this is memory for episodes involving cooperation and cheating. However, previous studies only examined source memory for cooperation and cheating, and neglected destination memory. The current study involved an event-related potential (ERP) experiment exploring destination memory and its retrieval-relevant ERP correlates in the social dilemma game. Participants interacted with virtual partners in the game, where both players were assigned either cooperation or cheating. Their destination memory for cooperative and cheating behaviors was later tested. Behaviorally, a clear self-positivity bias (i.e., enhanced memory for self-relevant positive information) was revealed: destination memory was more accurate for cooperation than cheating. The ERP correlates were also considered since they could reveal whether cooperation and cheating influenced different subprocesses of destination retrieval differently. Results indicated that the familiarity-driven FN400 and the recollection-based late positive complex (LPC) were more widely distributed or enhanced for cooperation than for cheating. In addition, late posterior negativity (LPN), which indexes efforts to reconstruct encoding episodes and evaluate retrieval outcome, lasted longer temporally for cooperation versus cheating, which might reflect greater difficulty in binding the self with morally unfavorable cheating behaviors. Altogether, both behavioral and ERP results constitute evidence for the self-positivity bias.