Before the members of a random crowd of people can constitute something in the nature of a group in the psychological sense of the word, a condition has to be fulfilled; these individuals must have something in common with one another, a common interest in an object, a similar emotional bias in some situation or other, and ('consequently', I should like to interpolate) 'some degree of reciprocal influence' (p. 23). The higher the degree of 'this mental homogeneity', the more readily do the individuals form a psychological group, and the more striking are the manifestations of a group mind.
