Venting and gossiping in conflicts: Verbal expression in ultimatum games

Conflicts often lead to expression of emotion to unrelated parties. We study non-instrumental verbal expression in binary ultimatum games, where receivers can comment either privately or to a third-party audience prior to accepting or rejecting the offer. The potential for gossip is sufficient to induce image concerns in senders, resulting in fairer offers in the audience treatment. Consequently, despite insignificant effect on receivers' behaviour, the possibility of verbal expression to an audience is found to increase co-operation and hence welfare. There is demand for verbal expression even when it is unobserved or not triggered by negative stimulus.