Abstract
Recent research indicated a general bias to follow a faster pedestrian in a simple egress task in both a real-world and an immersive virtual environment. Here, we extend previous work to investigate open questions regarding group size. In particular, do participants choose to follow faster or smaller groups? Two online experiments were conducted using the same general setup in which participants (N = 60 each) viewed two sets of virtual pedestrians walking towards a pair of doors on each side of the room. Participants were required to select one of the two doors via key press and were cued to respond when pedestrians had exited the room. Experiment 1 presented same-sized groups exiting of one two, three, or four pedestrians per side. These group sizes were selected to validate previous research using pairs of pedestrians and extend to larger groups. One group exited at one of three speeds (1.0m/s, 1.5m/s, or 2.0m/s), and the other group walked towards the opposing door at a constant speed of 1.5m/s, then the groups switched sides. This yielded six total trials per group size for a total of 24 randomly presented trials. Results were similar to previous in-person real world and immersive VR studies indicating a general bias to follow a faster groups; however, the increase in group size decreased the likelihood to choose the faster group. This effect may be attributable to attentional demands or a noisier stimulus. Experiment 2 presented both symmetrical and asymmetrical group sizes walking at the constant speed (1.5m/s). Results indicated that participants chose to follow smaller groups especially when the number of pedestrians increased above one. These results help to characterize the social influences on pedestrian egress behavior. Ongoing work examines interactions between speed and group size.