We compared the behavior of groups and individuals in a two-person trust game. The first mover in this game, the sender, receives an endowment and can send any part of it to the responder; the amount sent is tripled, and the responder can then return to the sender any portion of the tripled sum....

Although reciprocity is a key concept in the social sciences, it is still unclear why people engage in costly reciprocation. In this study, physiological and self-report measures were employed to investigate the role of emotions, using the Power-to-Take Game. In this 2-person game, player 1 can...

We report an experiment on the effect of intergroup competition on group coordination in the minimal-effort game (Van Huyck et al., 1990). The competition was between two 7-person groups. Each player in each group independently chose an integer from 1 to 7. The group with the higher minimum won...