The concept of ‘primary groups’ is a significant of C.H. Cooley to the social thought. Building black of human societies throughout the world history.

Characteristics of Primary Group:

(a) Dominance of primary or face-to-face relationships: Primary groups are characterized by close and intimate relationships. These exists a face-to-face relationship among the members. In primary Groups everyone knows everyone else; one’s name and fame, one’s status, wealth, occupation, level of education etc.

(b) Small in size: Primary groups are generally small in size, because its consists of few members. Size of primary groups should be small if the relations among members are to be close personal and intimate. ‘ 

(c) Physical proximity or nearness: Face-to-face relations can be found only when members reside in particular area more or less permanently. Seeing and talking with each other facilitates the exchange of ideas, opinions and sentiments. 

(d) Durability of the groups: Primary groups are relatively a permanent groups. Other things equal, the longer the groups remains together, the more numerous and deeper are the contacts between its members. 

(e) Similarity of background: The members of the primary groups may have more or less the same background. These must be some approximations in their levels of experience. Each must have something to contribute to give as well as to take.

(f) Shared interest: The shared interests of the groups also hold them together, any interest becomes focused and enriched in the group process. Since all are working for a common cause each acquires stimulation and a heightening of the emotional significance of the interest. 

Secondary group : 

In the secondary groups, the relationships secondary, relatively impersonal contractual task oriented, hence limited focus of its activities.

Characteristics of Secondary groups : 

(a) Dominance of secondary relations: The relationships that are found with hi secondary groups are formal indirect impersonal and secondary for example the relationship between teacher and students. 

(b) Large in size: The secondary groups are generally large in size incomparision to primary groups that may thousands of members. Trade union, corporation, international association, etc. are secondary groups and they have thousands of members. 

(c) No physical basis: Secondary groups are not necessarily characterized by physical proximity. Many secondary groups are not limited to any definite area. The members such a groups are scattered over vast area. 

(d) Nature of membership: Membership in the case of secondaiy groups in mainly voluntary. Individuals are at liberty to join or go away from the groups, for example : they are at liberty to join political parties. 

(e) Specific ends and interest: Secondary groups are formed for the realization of some specific interest’s ends. They are often called ‘Special interest groups’. Members are interested in the groups because they have specific ends to aim at.

(f) Nature of group control: Informal means of social control are loss effective in regulating the relations of members. Moral control is only secondary formal means of social control such as law, legislation, police, court etc. are made use of to control the behavior of members.