1) Reciprocal Relations:
The members of a group are inter-related to each other. Simply, a gathering of persons cannot form a group. Mutual relations are considered essential for the formation of a social group.
2) Sense of Unity:
A sense of unity is essential for every group. Group members are tied by a sense of unity. By virtue of such a sense, members of a group develop loyalty or a feeling of sympathy among themselves.
The members of a social group develop a sense of "we" feeling among them. "We-feeling" fosters co-operation among members and helps to defend their interests collectively. They treat others as outsides and try to make their group prosperous and self- sufficient.
4) Common interests:
The interests and ideals of a group are common. In fact, people from the group for the fulfillment of their common objectives or interests.
5) Group Norms:
Every group has its own rules and norms, which the members are supposed to follow. The group exercises control over its members through the norms.
6) Similarity of Behavior:
As the interests, ideals and values of the persons of a group are common; they behave in more or less similar way for the achievement of common interests.
Groups are permanent or temporary in nature, some groups like the crowd, mob etc. are temporary and unstable. But group like family is relatively permanent and stable in nature.
8) Groups are Dynamic:
Social groups are not static. They are dynamic. The rate of change may be slow or rapid. Due to internal or external pressures, groups undergo changes.