The computer visualization ('virtual reality') studies
One of the aims of the present project was to develop an experimental simulation that was both engaging and ethically sound. We therefore compared two types of experimental simulation to determine which was more suitable for further development: (i) a visualization (‘virtual reality’) design, and (ii) a room evacuation design.
The visualization developed by the team in Nottingham was an animation of a crowd evacuation from an underground railway station, and modelled on a computer game (using similar graphical techniques and user interface).
The ‘task’ facing the user is to evacuate the station as soon as possible, while at the same time facing bottlenecks caused by the rest of the crowd. The user also has to make decisions about whether to stop and help four people who are apparently injured. Within this design, we were able to vary key dimensions, such as the appearance of the characters in the evacuation, and the number of other evacuees, and to enhance the urgency of exit through a varying ‘danger’ indicator.
Participants’ identity was varied by a vignette at the beginning of each trial which cast them either as group members or individuals in an aggregate crowd. We then looked at the number of times ‘injured’ characters were helped (or not) and the extent to which participants pushed characters out of the way. A post-test questionnaire assessed the role of shared identity, feelings towards others, and intentions to help.
Seventy-two people took part in the first experiment. While it turned out to be difficult to get people to think of themselves as group members (versus individuals) in the way we intended, there was nevertheless a correlation between feelings of psychological ‘groupness’ and the amount of helping. That is, the more people saw themselves as group members, the more likely they were to stop and help fallen characters – even though such action delayed their own exit. This result was replicated in a student project on 40 participants using a different vignette. (Thanks to Becky Powell for this work.) In both cases, the more people saw themselves as group members, not only did they help more, but on the subjective (questionnaire) measures they cared for others more and expressed a greater desire to help.
A third experiment in which 62 people took part eliminated potential problems with the design but weakened the identity manipulation further. There was more helping in the ‘group identity’ than the ‘personal identity’ condition but this difference was not statistically significant. Forty people took part in a fourth experiment, which was carried out as a student project. (Thanks to Andy Hardwick for this work.) This study used a different vignette and identities to the previous ones (‘football supporters’ instead of ‘students’). Those in the ‘group identity’ condition displayed significantly more helping behaviour than those in the ‘personal identity’ condition. There was some support for the idea that this behaviour was partly caused by positive feelings towards ingroup members.
In each of these studies, while there was some evidence in support of the role of shared identity on the helping and questionnaire measures, there was no pattern in the ‘pushing’ data. Observations of participants in these studies, as well as at a public exhibition at the Royal Society, led us to conclude that there was a problem with the on-screen instruction at the beginning which explains how to push other characters. This could be read as an encouragement to push in what might be perceived as a ‘game’. The visualization was modified three times within the project, each time achieving greater realism. But it was beyond the scope of the current project to address this problem in the instructions through further changes to the software.
Overall, the visualization studies support the conclusion that, where there is a strong sense of collective identity, there will be mutual concern and helping. Importantly, people with a strong shared identity in these studies tended to help the fallen character even though this meant delaying their own exit. Where the sense of shared identity was weak, on the other hand (either through our deliberate manipulation or because the manipulation was weak), there was less mutual concern and less helping. The significant results that were found were therefore in line with the self-categorization account of mass emergency evacuation behaviour.
In terms of the aim of developing an experimental simulation that was both engaging and ethically sound, our conclusion is that the visualization method has more potential than the room evacuation method. There was more psychological engagement with the visualization than the room evacuation method: participants took the visualization more seriously overall. The visualization also included more measures (more opportunities for helping versus personally selfish behaviours) than the room evacuation.
For details of studies and results, see:
Drury, J., Cocking, C., Reicher, S., Burton, A., Schofield, D., Hardwick, A., Graham, D., & Langston, P. (2009). Cooperation versus competition in a mass emergency evacuation: A new laboratory simulation and a new theoretical model. Behavior Research Methods, 41, 957-970.
doi:10.3758/BRM.41.3.957
Link to images from the program