Tim Shields: Chapman University

We describe results of a study in trust-based exchange that supports the proposition that humans perceive intention not only through what others do but also through what others choose not to do. Crucial to this proposition is the notion that trust-based exchanges entail decision dilemmas where mutually exclusive goals are traded off and the forgone opportunities produce clues about our intent – affecting others’ reactions. To manipulate the availability of foregone opportunities, we used two versions of the trust game in a 1×2 between subjects design. In two experimental trust games, the action space governing trustors’ transfers was manipulated to examine the effects on trustors’ transfers and trustees’ returns. In the “all-or-nothing” game the trustor could transfer either $10 (all) or $0 (nothing), while in the “continuous” game the trustor could transfer any amount between $10 and $0. In both games, the trustee received the tripled transfer and then could return any amount (to trustor). Trustors transferred significantly more in the all-or-nothing game than in the continuous game. However, higher initial transfers in the all-or-nothing game did not lead to larger returns. To the contrary, conditional on $10 transfers, on average trustees returned significantly less in the all-or-nothing game than in the continuous game. Although the all-or-nothing action space results in greater wealth overall, trustors do not benefit from this increased wealth. These results suggest that the availability of alternative options is paramount in shaping social behaviors.