Panic, Irrationality, and Herding: Three Ambiguous Terms in Crowd Dynamics Research

Table 4

A summary of the conclusions and the recommendations associated with each of the three terms.

Panic	Conclusions	(i) Panic lacks a formal clear definition; (ii) Panic lacks a unified well-defined characterisation; (iii) Panic cannot be tested as a verifiable hypothesis; (iv) Panic is not theoretically well-conceived; (v) Panic is not empirically well supported; (vi) Despite lack of clear definition, the term panic persists to be increasingly mentioned in the evacuation dynamics literature, particularly in numerical studies; (vii) Alternative theories have been proposed by social scientists challenging the theory of panic; (viii) There is a sharp divide between how social and physical scientists see the panic theory and its relevance to disaster research
	Recommendations	(i) The evacuation dynamics literature does not benefit from the use of the term panic as it pushes numerical studies towards unverifiable assumptions and non-testable model formulations; (ii) The evacuation dynamics literature does not seem to benefit from the use of the term panic as it pushes empirical studies away from human experiments towards alternatives such as experiments with insects/animals; (iii) The question of panic can be substituted by operationalizable questions, such as, how fear and stress influences collective behaviour in disasters
Irrationality	Conclusions	∙ Irrationality is an implied notion in the panic theory, thus, same comments largely apply as above
	Recommendations	(i) Irrationality does not need to be associated with panic (as a feature of panic behaviour). The two can be dissociated. Behavioural rationality could be investigated in its own term without the link to panic; (ii) Rationality can be re-framed as (replaced by) optimality of behaviour so it can be measured/tested; (iii) Measuring rationality requires clear points of reference; (iv) Rationality could be measured at both collective and individual levels, each requiring their own reference points; (v) Experimental studies could give insight into how rational (optimal) human evacuation is, and under what circumstances their behaviour becomes more/less rational; (vi) Numerical simulation models can further our understanding about how we can enhance collective optimality (rationality) in emergency response
Herding	Conclusions	(i) Empirical studies do confirm the role of social influence in evacuation behaviour; (ii) There is relative consensus on the definition of the term herding, although not perfectly; (iii) Herding is an animalistic and rather sensational term; (iv) The term herding implies that the direction of social influence is always “imitation” (not always the case, sometimes the opposite “avoiding others” is the case); (v) Herding implies that the direction of social influence is always following the majority (not always the case, sometimes, following the minority is the case); (vi) Herding implies that social influence is the single dominant factor in decision making (not always the case, often people make a trade-off between various factors); (vii) The empirical literature so far has suggested that people do show tendency to imitate when it comes to evacuation movement initiation or decision change initiation.; (viii) Some empirical studies have shown opposite tendency to herding when it comes to direction choice making especially in heavily crowded situations; (ix) Contextual factors such as the crowding level, the stress level or the level of environmental familiarity have shown to change the magnitude and direction of the social influence
	Recommendations	(i) The term social influence is more suitable than the term herding.; (ii) Herding does not need to be associated with panic (as a feature of panic behaviour). The question of social influence can be legitimately investigated in its own terms; (iii) The question about the role of social influence should be studied in association with different specific aspects of the behaviour. The effect varies across various behavioural aspects.