The existing literature on crowd behaviour involves a variety of deﬁnitions, descriptions, views and explanations. Several of them will be addressed in this chapter to lay the groundwork for the deﬁnition, focus and aspects that are considered necessary to proceed in understanding crowd behaviour. Crowd behaviour is the behaviour that is conducted by individuals who gather in a crowd. However, what is exactly meant when talking about crowds and their behaviour? In everyday life, the word crowd is used to indicate a range of situations that involve an assembly of persons. For example a crowd at a festival, or a crowd on the internet to buy tickets for a concert. Usually, the context in which the word ’crowd’ is used indicates what type of group is meant in terms of size, duration, composition, motivation, cohesion and proximity of individuals. The crowd example in chapter 1 of the beach festival illustrates this meaning through context. Crowd behaviour at the festival is for instance clearly different from crowd behaviour in the shopping street (see the boxes 1-3 examples in chapter 1). In the shopping street the crowd consists of identiﬁable small groups, each pursuing their unique shopping goals, but all of them have the goal to shop. At the festival different groups can be identiﬁed. J* belongs to several of these groups. A small group of companions with whom J* came to the festival. But also a larger group in which J* and others are dancing in front of the stage. The dancers share the way of fulﬁlling their goal to enjoy music, while the shoppers differ in behaviour to fulﬁl their goal as they are not all heading for the same shop. The differences between the crowds are hard to catch in a deﬁnition as they are situation and time dependent what kind of group is dealt with. In the ﬁeld of crowd research there is no consensus on the deﬁnition of a crowd. The deﬁnitions evolve around the concept of a gathering (Challenger, Clegg, & Robinson, 2009b) accompanied by a description of what binds the individuals in the crowd. To give some examples - “A crowd is a temporary gathering of individuals who share a common focus of interest” (Forsyth, 2006). For Reicher (2001) on the other hand, a crowd is only a crowd when “individuals share a social identity” (Reicher, 2001). Regardless of the differences in the core of these deﬁnitions, they all share the notion of a number of people in the same place at the same time, i.e. a gathering (Loﬂand, 1985). Most deﬁnitions include the concept of a psychological group by adding a
binding between the individuals in a physical crowd, i.e. a social relationship (Forsyth, 2006, p. 4). Depending on the theorist this social relationship is deﬁned as a shared commonality, such as fate, goal, social identity, interaction, structure, inﬂuence, interdependence (Forsyth, 2006; Brown, 2000). In this thesis a deﬁnition of a crowd is needed that allows for studying crowd behaviour patterns and the dynamics of these patterns with as little assumptions as possible. The minimal description starts from a notion of a group. A group is deﬁned here as a set that holds at least two elements, without any other characteristics being speciﬁed. In the context of a crowd a group can be any set of two or more individuals, for instance people that are behaving in the same way can be attributed as a group. To refer to a crowd gives more information about a group of individuals as a crowd involves the co-presence of individuals at a speciﬁc physical location. When crowds are addressed by researchers or media this usually involves the rise and change of a psychological group, similarly to the deﬁnitions that are used, addressed in previous paragraph. However, a crowd does not necessarily need to be a psychological crowd, moreover it is relevant to capture this process of being part of a psychological group to gain understanding of crowd behaviour. In this thesis the deﬁnition...