Social influence in a virtual tunnel fire--influence of conflicting information on evacuation behavior.

Evacuation from a smoke filled tunnel requires quick decision-making and swift action from the tunnel occupants. Technical installations such as emergency signage aim to guide tunnel occupants to the closest emergency exits. However, conflicting information may come from the behavior of other tunnel occupants. We examined if and how conflicting social information may affect evacuation in terms of delayed and/or inadequate evacuation decisions and behaviors. To this end, forty participants were repeatedly situated in a virtual reality smoke filled tunnel with an emergency exit visible to one side of the participants. Four social influence conditions were realized. In the control condition participants were alone in the tunnel, while in the other three experimental conditions a virtual agent (VA) was present. In the no-conflict condition, the VA moved to the emergency exit. In the active conflict condition, the VA moved in the opposite direction of the emergency exit. In the passive conflict condition, the VA stayed passive. Participants were less likely to move to the emergency exit in the conflict conditions compared to the no-conflict condition. Pre-movement and movement times in the passive conflict condition were significantly delayed compared to all other conditions. Participants moved the longest distances in the passive conflict condition. These results support the hypothesis that social influence affects evacuation behavior, especially passive behavior of others can thwart an evacuation to safety.