A small group is typically one where the collection of people is small enough that all members of the group know each other and share simultaneous interaction, such as a nuclear family, a dyad, or a triad. Georg Simmel wrote extensively about the difference between a dyad, or two-member group, and a triad, which is a three-member group. In the former, if one person withdraws, the group can no longer exist. We can think of a divorce, which effectively ends the “group” of the married couple or of two best friends never speaking again. In a triad, however, the dynamic is quite different. If one person withdraws, the group lives on. A triad has a different set of relationships. If there are three in the group, two-against-one dynamics can develop, and a majority opinion may form on any issue.
Small groups generally have strong internal cohesiveness and a sense of connection. Small groups may face challenges when trying to achieve large goals. They can struggle to be heard or to be a force for change if they are pushing against larger groups.
It is difficult to define exactly when a small group becomes a large group. Perhaps it occurs when one group grows so large that there are too many people to join in a simultaneous discussion. Sometimes it occurs when a group joins with other groups as part of a movement. These larger groups may share a geographic space, such as a fraternity or sorority on the same campus, or they might be spread out around the globe. The larger the group, the more attention it can garner, and the more pressure members can put toward whatever goal they wish to achieve. At the same time, the larger the group becomes, the more the risk grows for division and lack of cohesion.