Fig. 1.

Time course of a single trial. At the beginning of each trial, a participant was presented with the current trial number followed by choices made by P1–P7. Once a participant pressed the ‘Begin’ button, P1’s choice was displayed on the screen. After 2 s, P2’s choice was displayed and so on. The seven predecessors’ choices were displayed sequentially, and the interval between displaying every predecessor’s choice was fixed at 2 s. After P7’s choice was displayed, P8 drew a ball by pressing the ‘Draw ball’ button. P8 then had 10 s to make a decision after observing his or her private signal.