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.
The most remarkable and also the most important result of the formation of a group is the 'exaltation or intensification of emotion' produced in every member of it (p. 24). In McDougall's opinion men's emotions are stirred in a group to a pitch that they seldom or never attain under other conditions; and it is a pleasurable experience for those who are concerned to surrender themselves so unreservedly to their passions and thus to become merged in the group and to lose the sense of the limits of their individuality. The manner in which individuals are thus carried away by a common impulse is explained by McDougall by means of what he calls the 'principle of direct induction of emotion by way of the primitive sympathetic response' (p. 25), that is, by means of the emotional contagion with which we are already familiar. The fact is that the perception of the signs of an emotional state is calculated automatically to arouse the same emotion in the person who perceives them. The greater the number of people in whom the same emotion can
