Trust between individuals and groups: Groups are less trusting than individuals but just as trustworthy

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. In a 2x2 design, the players in the roles of sender and responder were either individuals or groups of three players (who conducted face-to-face discussions to decide on a collective group strategy). We found that groups in the role of sender sent smaller amounts than individuals, and expected lower returns. In particular, groups sent nothing more often than individuals did (and were more likely to do so when the responder was another group). Groups and individuals in the role of responder returned on average the same fraction of the amount sent. Hence, we conclude that groups are less trusting than individuals, but just as trustworthy.