Perceived threats and 'stampedes': a relational model of collective fear responses

Lead Research Organisation: University of Sussex
Department Name: Sch of Psychology


This research will address the question of how people respond collectively to acute states of perceived emergency. Both in the UK and globally, the occurrence of terrorist attacks has been associated with an increase in collective flight incidents - often called 'stampedes'. Most have been false alarms. In the case of the incidents in Oxford Street, in 2017, for example, hundreds ran from what they thought was gunshots, and many more joined in when they saw people running, in a cascade of secondary effects. These events are often distressing for those involved. Some of them result in injury and even deaths.

'Stampedes' in response to perceived hostile threats raise the following questions: When and how is a signal perceived as threatening? When and how do people flee? When do they follow (or ignore) others? What is the role of other groups (authorities, emergency services) in communicating threat? When do these incidents become disorderly?

Yet despite their social and psychological significance, these incidents are poorly understood, and an adequate theoretical understanding is currently lacking. Explanations in terms of hypervigilance are necessary but insufficient. They don't explain either how threat perceptions are shared or the collective nature of 'stampedes'. Explanations in terms of 'crowd panic' are also inadequate, despite dominating public discourse. They cannot account for the evidence of discrimination and restraint in these evacuation events.

This project will provide the first systematic evidence on the nature and dynamics of human 'stampedes' in response to perceived hostile threats. We will develop a new model, based on the social identity approach (a theory of our psychological group memberships) and social appraisal theory (which focuses on the social and emotional information we infer from others' responses). We argue that 'who we are' - which can vary across contexts - shapes perceptions of threat, emotional appraisal, and social influence. A distinctive claim is that crowd events such as these are intergroup relationships. Therefore, as well as examining crowd members' perceptions and behaviour, we will examine those of emergency responders, and the relationship between responders' communicative acts and public behaviours.

Previous limitations in understanding 'stampedes' in response to hostile threats are due to a lack of appropriate methodology as much as the paucity of theory. We will address these limitations through a programme of research comprising three strands. First, a case study strand will systematically describe and compare known examples (e.g., Nice fire-cracker 'stampede' of 2018, evacuation at Westfield shopping centre, 2018), as well as provide detailed analysis, using interview and archive data, of a contemporary and a historical incident. Second, experiments using Virtual Reality will allow us to manipulate and control variables, such as group relationships and norms, and to measure direction and speed of flight response, in order to test systematically our hypotheses about the roles of identity and appraisal. Third, given the role of emergency responders and authorities in communicating threat, we will observe their exercises and carry out a field experiment to measure their influence (intended and unintended), including effects of their messages. Together these studies will enable us to determine when and how a signal is perceived as threatening, whether and how people flee, when people follow (or ignore) others, and the role of the emergency services in this.
Understandings of public responses to perceived emergencies have implications for emergency policy and practice and for public debate. Therefore, as well as a new theoretical model, outcomes from this project will include new emergency guidance, and new public discourse on this topic.

Planned Impact

The increased incidence of public flight in response to perceived hostile threats makes this project timely for a number of public services and government bodies responsible for preparedness and response to emergencies. The challenge for the authorities is how to maintain public alertness and build trust in their communications to the public, whilst avoiding acting in ways that amplify risk unnecessarily. Currently, the lack of adequate understanding of public behaviour in these incidents is a problem for the emergency services and the bodies that advise them. This research will significantly enhance the evidence-base on public behaviour in these events. The benefit for the emergency services, the organizations that provide guidance, and the public themselves is more efficient preparedness and response, and ultimately greater public safety.
There are benefits specific to particular sectors and organizations. For the fire and rescue service (FRS), the new research will improve scenario planning and execution, enhancing their training and preparedness for incidents. Local Resilience Forums (LRFs) will benefit through developing understanding of public information needs in the immediate aftermath of a possible incident. Through improving their scenarios, they will be better able to test the credibility of their planning assumptions, planning arrangements and training infrastructure.

Specifically, this research will provide Staffordshire Civil Contingencies Unit (CCU) and Staffordshire FRS with new learnings and better training exercises, which we will help re-design. Exercises cost considerable resources. Our findings will contribute to more veridical exercises, through incorporating more complete information about public behaviour. This will produce better value for money and better preparedness when dealing with actual events. The benefits to Staffordshire CCU and FRS will transfer to LRFs, fire and police services across the country through the national forums these organizations are part of.

The Civil Contingencies Secretariat (CCS) is the department of the Cabinet Office responsible for emergency planning. They produce the National Risk Assessment, used by LRFs in their emergency planning. The research will provide information CCS have requested, such as how the public respond to threats in different locations and the role of different sources of information. This will help the CCS with recommendations on communication with the public.
Public Health England design and commission exercises and provide guidance on likely public behaviour in the event of an emergency. As well as benefiting from the enhanced evidence-base, they will benefit from the improvements in terms of psychological realism we will be able to provide to their exercise planning.

The research will be beneficial to those who manage crowd safety, including at music events, transport hubs and shopping centres, in the UK and internationally. Professionals involved in engineering and design for evacuations will also benefit; they will be able to develop more effective and accurate evacuation models. The research will also benefit regulatory frameworks, and will inform discussion about new guidance on safety at sports grounds.

The public will benefit, both in terms of their safety, but also in terms of public discourse. In criticizing the notion of 'stampedes' and irrational 'panic', and in disseminating knowledge of the conditions under which public flight occurs, we will provide a space for new language to emerge. Our work will therefore contribute towards a more informed public discussion of threats and collective flight responses. What is the balance between withholding information on threat and practices that might encourage public flight? Public discourse will therefore benefit through stimulating an informed public discussion. In this way, our work is of importance both at the level of individual understanding and of societal wellbeing.


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Description We reviewed incidents in the UK over ten years involving a 'false alarm' to a perceived terrorist threat. In the period, we identified 496 genuine attacks (36 in England, 4 in Scotland and 456 in Northern Ireland) and 112 false alarms. 25 of the false alarms involved urgent evacuations of the type that have been called 'stampedes'. When correlating the false alarms and urgent responses with real attacks, we found that it wasn't simply the number of attacks that drove the false alarms, but the psychological relevance of the attacks: Islamist-inspired attacks and attacks with large numbers of casualties were the ones most likely to be associated with subsequent false alarms. In addition, the official threat level was also associated with false alarms. Most of the false alarms took place in transport hubs and shopping centres. We also found that even in urgent responses in which many people ran and some were trampled there was a variety of public behaviour including many incidents of cooperation.

We have almost completed development of a virtual reality program simulating public response to a perceived marauding terrorist attack, which we will be using in our experiments.
Exploitation Route We are in discussion with the following organizations on how they can use our findings to assist with public communication policies and practices in the event of possible terrorist attacks: Civil Contingencies Secretariat, Home Office, Dstl, CPNI, Transport for London.
Sectors Government, Democracy and Justice,Security and Diplomacy,Transport

Description Presentation and discussion meeting with Civil Contingencies Secretariat 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Presentation of initial findings of our review of false alarm incidents. Dialogue with government departments on these findings and their implications for policy and practice (e.g. communications with the public).
Year(s) Of Engagement Activity 2021