Fig. 1: Third-party punishment game followed by a trust game.
From: Trust within human-machine collectives depends on the perceived consensus about cooperative norms
First, three players participate in a third-party punishment game. In this game, Helpers and Punishers are initially given resources, while Beneficiaries are not. Then, the Helper makes a choice between sharing their resources equally with the Beneficiary, or keeping all their resources to themselves. This choice is illustrated by the arrow labeled as “Share?''. The Punisher observes the action of the Helper, and then makes a choice between punishing or not punishing the Helper when they do not share. This choice is illustrated by the arrow labeled as “Punish?” with the eye icon underneath the arrow emphasizing that the Punisher has observed the Helper’s action before deciding. This punishment is costly to the Punisher; it requires them to forego one quarter of their resources in return for making the Helper who did not share lose half of theirs. The Helper is aware that the Punisher observes their choice to share or not, and that the Punisher may choose to punish them if they do not share. Second, a new player—the Trustor—is paired with either the Helper or the Punisher, who observes either the Helper’s or the Punisher’s behavior in the third-party-punishment game depending on the experimental condition as illustrated by the arrow marked by an eye icon starting from the Trustor. All other players in the third-party-punishment game are aware of this fact (i.e., the existence of the Trustor and whom the Trustor is paired with). The Trustor then participates in a trust game where they are given resources that they may send to the Helper or to the Punisher depending on the experimental condition, knowing that any resources they send will be tripled, after which the Helper or the Punisher chooses how much of the tripled amount to return to the Trustor.
