We enrich the choice task of responders in ultimatum games by allowing them to independently decide whether to collect what is offered to them and whether to destroy what the proposer demanded. Such a multidimensional response format intends to cast further light on the motives guiding responder...

We introduce the uncertainty of psychological motivation into a reciprocity model and explore its implications on behavior. We extend the Sequential Reciprocity Equilibrium in extensive-form games (Dufwenberg and Kirchsteiger, 2004) to a broader class of incomplete information games. We use this...