Note on the drawing power of crowds of different size.

This study reports on the relationship between the size of stimulus crowd, standing on busy city street looking up at building, and the response of passersby. As the size of the stimulus crowd was increased greater proportion of passersby adopted the behavior of the crowd. The results of this study suggest modification of the Coleman and James model of the size of freeforming groups to include contagion assumption. Ill typical urban setting, when group of people engage in an action simultaneously, they have the capacity to draw others into the crowd. The actions of the initial group may serve as stimulus for others to imitate this action. A careful analysis of the details of crowd formation is of obvious interest to society in which collective action plays an increasingly important part in social life. One theoretical formulation that bears on this problem is that of Coleman and James (1961). Coleman and James assumed that there is natural process by which free-forming groups acquire and lose members and thus reach specific maximum sizes. They have developed model that generates size distribution that closely approximates the actually observed size distribution of many thousands of groups. The central assumption of their model of acquisition and loss are a constant tendency of group member to break away, independent of the group, thus producing