It will be conceded at the first glance, without hesitation, that the sociological structure of a group is essentially modified by the number of the individuals that are united in it. It is an everyday experience - yes, it is almost to be construed from the most general social-psychological presuppositions - that a group of a certain extent and beyond a certain stage in its increase of numbers must develop for its maintenance certain forms and organization which it did not previously need; and that, on the other hand, more restricted groups manifest qualities and reciprocal activities which, in the case of the numerical extension, inevitably disappear. ... - American Journal of Sociology, Vol. 8, p. 2, George Simmel.

. . . The number of his fellows with whom a man can maintain easy personal intercourse varies with individual variations, with the conditions of work, and with the time which any body of workmen spend together. Perhaps it does not often exceed eighty, and is normally about twenty or thirty. I do not know of any important attempt to organize mechanical work in relation to that fact, though sometimes the success of a "gang system" may accidentally depend upon it. An American engineer said, I was once told, that the only piece of work which he had thoroughly enjoyed was the making of the Key West Railway, where each pier was placed upon a separate rock in the sea, and was erected by a small and separate group of men who came to know each other thoroughly. In armies it is found necessary, if any measure of comfort and contentment is to be secured, that the officers in each regiment and the men in each company or platoon should be deliberately formed into groups, generally numbering about twenty-five; and one of the responsible organizers of a great Insurance Company told me that he consciously aims at bringing groups of twenty or thirty officials into regular social intercourse. Those Universities are most successful where, by an arrangement of "colleges" or "dormitories," the students are divided into somewhat larger groups; and if no arrangement of the kind has been made by the authorities, clubs or cliques, in forms sometimes inconsistent with other conditions of desirable social life, spontaneously make their appearance. - Wallas, The Great Society, pp. 333, 334.

Simmers article appeared in 1902, and the book by Wallas thirteen years later, both doubtless independent of Cooley's influence. Other independent evidence on the size of a primary group is found in discussions about the proper number of seats in a schoolroom which is to be in charge of one teacher, and the number of teachers in a building which is to be in charge of one principal. Thirty pupils to a teacher is most often named as the standard, with a range of from two or three to ten in either direction.1

. . . The principals interviewed have expressed themselves almost unanimously as to the proper size, maintaining that a school should number only so many teachers as the personal acquaintance and influence of the principal can effectively reach; and the outside limit is about thirty, with 1,500 children. Many would much prefer to limit the number of children to 1,000. - McMurry, Elementary School Standards, p. 186.

During the writer's connection with one school the number of teachers has grown from twenty-five to forty-five. This has effected a radical transformation in the character of our faculty simply as a group. Formerly we could all meet for supper and a social time at any one of our homes, and we did so most frequently, the members of our families often being included. Now a party for the faculty is an undertaking of such magnitude that it is attempted only once or twice a year, and it has been several years since the children were included. Our daily work is now of greater variety, carried on in more rooms, spread over more ground, and with a more complicated program, so that one of us may not see some of his colleagues for weeks, instead of meeting most of them many times a day as in earlier times. The weekly faculty meeting used to be quite informal and was largely devoted to visiting, many of the women having fancywork along; now it is a business meeting with much routine to put through, and the president holds it to parliamentary rules. Formerly only some unusual necessity would keep one of us away from the general exercises in the morning, lest we lose touch with the school; now it is the exception to attend, and all of the important communications come to us on paper. Therefore, while the number of persons in our group has nearly doubled, the opportunities for getting acquainted with any of them have lessened, with the result that some of us might not be able to call some of our colleagues by name if we should see them among strangers, let alone the members of their families. In fine, we have ceased to be a primary group simply because there are so many of us.

1 Ballou, High School Organization, p. 32.

Modern methods of urban transportation and communication - the electric railway, the automobile, and the telephone - have silently and rapidly changed in recent years the social and industrial organization of the modern city. . . . These changes in the industrial organization and in the distribution of population have been accompanied by corresponding changes in the habits, sentiments, and character of the urban population.

The general nature of these changes is indicated by the fact that the growth of cities has been accompanied by the substitution of indirect, "secondary," for direct, face-to-face, "primary" relations in the associations of individuals in the community. . . .

Touch and sight, physical contact, are the basis for the first and most elementary human relationships. Mother and child, husband and wife, father and son, master and servant, kinsman and neighbor, minister, physician, and teacher; these are the most intimate and real relationships of life and in the small community they are practically inclusive.

The interactions which take place among the members of a community so constituted are immediate and unreflecting. Intercourse is carried on largely within the region of instinct and feeling. Social control arises, for the most part spontaneously, in direct response to personal influences and public sentiment. It is the result of a personal accommodation rather than the formulation of a rational and abstract principle.

... In a great city, where the population is unstable, where parents and children are employed out of the house and often in distant parts of the city, where thousands of people live side by side for years without so much as a bowing acquaintance, these intimate relationships of the primary group are weakened and the moral order which rested upon them is gradually dissolved.

Under the disintegrating influences of city life most of our traditional institutions, the church, the school, and the family, have been greatly modified. The school, for example, has taken over some of the functions of the family. It is around the public school and its solicitude for the moral and physical welfare of the children that something like a new neighborhood and community spirit tends to get itself organized.

The church, on the other hand, which has lost much of its influence since the printed page has so largely taken the place of the pulpit in the interpretation of life, seems at present to be in process of readjustment to the new conditions. - American Journal of Sociology, Vol. 20, pp. 593, 594, R. E. Park, "Human Behavior in the City Environment."