One kind of primary group will now be selected for fuller analysis and illustration. Though it is most often given as typical of all, it may be conveniently called the congenial group to distinguish it from the others. Such a group consists of persons who habitually maintain direct communication with one another for the sake of the enjoyment they find in it. They must of course be persons who are in sympathy with one another, or at least without strong antipathies. For this reason the number must be small. An additional member means more than a proportional increase in the probability of discord, for he brings not only one new reaction, but at least as many as there are members already in the group. Thus in a group of three there are three pairs of persons and so three times as many chances of antipathy as in a group of two. In a group of four there are six pairs, in a group of five there are ten, and so on. But even this represents the relationship to be more simple than it really is, for the reaction between any two persons is modified by the mere presence of another, after the manner of catalysis in chemistry: the new member brings not only his own reaction with each of the others, but he also causes each of the other pairs to react in a somewhat different way. Then also, the larger the group the less the chance for each to express himself, because only one can have the attention of the group at a time. It is also more likely that some will be absent when the others are together, and the absentees will have difficulty in keeping abreast of the others in thought. It is rare, therefore, for a congenial group to include more than half a dozen persons. When it does it is certain to diminish in coherence through the formation of subgroups, and perhaps start on the road to dissolution.

Since a congenial group is a spontaneous growth, without formal organization, its membership is usually shifting and uncertain. A and B, for example, were students with a room in a central location; C and D were frequent callers; these four had similar work. E called occasionally and F rarely: these two were students in other departments. A was popular with all. B would probably not have been in the group if he had not roomed with A; he and C had little in common, but he and F enjoyed each other's company when they were by themselves. Somewhat after this manner a congenial group consists of a small nucleus of almost constant members, with a fringe of occasional members who each gives most of his time to one or more other groups.

The associations of adults are so largely controlled by remote ends that their congenial groups are difficult to identify. An old person does not fit into new groups easily; he still lives in the groups of his earlier life, keeping in touch with them by indirect communication; the casual observer merely sees the absence of any strong interest in surrounding persons. Children, on the other hand, spend much of their time in congenial groups. A teacher can find no more fascinating study, or one more helpful professionally, than these natural groupings which children form for themselves.

For boys' groups of the better sort, the following accounts are typical:

Five boys between the ages of nine and thirteen got together to work. All would go to one boy's home and help him with his chores, then go on to the next. This was fun - work turned to play. The leader of this group was not the oldest nor the largest, but one who could look serious and command - always could think of new stunts to do. He it was who proposed the building of a shack in one of the back yards with scraps of lumber picked up or given to them.

A group of six boys was established in the seventh grade through an interest in outdoor sports, especially baseball, hunting, and swimming. When at leisure they were always together. At parties and social affairs they formed a clique. When one member was ill the remaining five took turns staying at the bedside during the night. One of the boys fell and broke his arm; the others took his paper route, delivered the papers, and gave him the money. They would also come to play with him and cheer him up. One of the members had work to do before he could come out to play; the others would help him do it. But the unity of the group was not always one of harmony; they had frequent quarrels, though never very serious ones. They hated an untruth. When they found that one of their number had told a deliberate lie they punished him severely.

Last summer I watched a group of boys ranging between nine and twelve years of age on a playground near my home. Almost any time of day they could be seen - the same group each day. Once I noticed a strange boy, about the same age as the rest, come and ask to join in their game. But they refused blankly - no outsiders allowed. On another occasion a boy who had had more practice in playing ball than any in this little group came and offered his services as pitcher. But they refused him, even though they realized that he might be a great help in their play. One morning when the group gathered for play one of the members was not present. They all ran to his home and found that he had been set to the task of piling some wood in a shed. So they pitched in and helped him pile the wood. That done, they all returned to their play. One of the boys accidentally broke a window. They all contributed to the cost of replacing it, so that he had only his share to pay.

The gang spirit is strongest in the average boy during his thirteenth, fourteenth, and fifteenth years, when he is in the seventh, eighth, and ninth grades. Here is the way one writer describes this stage in a boy's growth:

The boy begins ... to feel more strongly than before the necessity of meeting certain other boys every day - to play a game, if favored by surroundings and good play traditions, but anyway to meet, for purposes which seem to him sufficient. His life is now in this companionship; it has become his milieu, his social complement, his world, as necessary to him as a mother to a little child. This relation pervades his life and everything he does. If he walks, swims, rides, makes jokes, converses, it is as a member of a horde. . . .

. . . His paramount desire now is to belong: to live and act, succeed or fail - to suffer if need be - not as an individual but as a member of a social whole made up of boys of his own age; and the effects of this new desire are seen in everything he does. ... - Lee, Play in Education, pp. 319, 320.