In repeated games, it is hard to distinguish true prosocial behavior from strategic instrumental behavior. In particular, a player does not know whether a reciprocal action is intrinsically or instrumentally motivated. In this paper, we experimentally investigate the relationship between...

In many cultures and industries gifts are given in order to influence the recipient, often at the expense of a third party. Examples include business gifts of firms and lobbyists. In a series of experiments, we show that, even without incentive or informational effects, small gifts strongly...

Unfair intentions provoke negative reciprocity from others, making their concealment potentially beneficial. This paper explores whether people hide their unfair intentions from others and how hiding intentions is itself perceived in fairness terms. Our experimental data show a high frequency of...