[Trust and cooperation: an experimental study of PD with choice of dependence]

This study examined the relationship between cooperation and trust in interpersonal trust formation. Previous studies of trust and cooperation using prisoner's dilemma (PD) games failed, methodologically as well as conceptually, to distinguish the former from the latter. In response to the criticism on the use of iterated PD games, and for the purpose of investigating dynamic relationship between trust and cooperation, an improvement in research methodology was recently proposed: namely, PD with choice of dependence (PD/D; Kakiuchi & Yamagishi, 1997; Yamagishi & Kakiuchi, 2000). We conducted an experiment to compare formation of trust relations in PD and PD/D. Result indicated a higher level of cooperation in PD/D than in PD. Further analysis of strategies used to build trustful relationship, where two partners trusted each other and reciprocated the other's trusting behavior, revealed that participants in PD/D adopted "cautious and unconditional cooperation strategy" rather than TFT strategy.