How communication increases interpersonal cooperation in mixed-motive situations

Evidence from two experiments indicates that task-related communication promotes cooperation in mixed-motive situations by activating interpersonal norms related to fairness and trust. In Experiment 1, task-related communication increased cooperation between individuals in a three-choice prisoner’s dilemma game (PDG-Alt) but task-unrelated communication did not. In Experiment 2, cooperation was increased both by sending a task-related message to one’s counterpart and receiving a cooperative task-related message from one’s counterpart. Mediation analyses revealed that task-related communication increased cooperation by activating fairness and trust norms (Experiments 1 and 2). Specifically, whereas sending (relative to receiving) a task-related message increased cooperation by activating fairness norms, receiving (relative to sending) a task-related message increased cooperation by activating trust norms (Experiment 2).