No effects of synchronicity in online social dilemma experiments: A registered report

Online experiments have become a valuable research tool for researchers inter-ested in the processes underlying cooperation. Typically, online experiments are asyn-chronous, participants complete an experiment individually and are matched with partners after data collection has been completed. We conducted a registered report to compare asynchronous and synchronous designs, where participants interact and re-ceive feedback in real-time. We investigated how two features of synchronous designs, pre-decision matching and immediate feedback, influence cooperation in the prisoners dilemma. We hypothesized that 1) pre-decision matching (assigning participants to specific interaction partners before they make decisions) would lead to decreased social distance and increased cooperation; 2) immediate feedback would reduce feel-ings of aversive uncertainty and lead to increased cooperation; and 3) individuals with prosocial Social Value Orientations would be more sensitive to the differences between synchronous and asynchronous designs. We found no support for these hypotheses. In our study (N = 1,238), pre-decision matching and immediate feedback had no significant effects on cooperative behavior or perceptions of the interaction; and their effects on cooperation were not significantly moderated by Social Value Orientation. The present results suggest that synchronous designs have little effect on cooperation in online social dilemma experiments.