Together these. two stimuli-drive 3 and crowd-determine the strength of the responses which will be made by individuals in the crowd. .If the drive stimulus is weak, as in the case, say, of an aggregate watching an excavation, no very vital crowd stimulus can be added to it. If the drive is strong, as fear of fire in a theatre, crowd stimulation can build up the total stimulation to great heights. Responses_ in ~he one case will be the weak ones of mere looking; in the other, they will consist of frenzied efforts ~o escape.