Both primary group and secondary group differ from each other in certain respects.
(1) Difference in size:
The size of the primary group is small as it consists of few members. Small size of the primary group helps its members to develop personal relations among themselves. On the other hand, secondary group is large in size. It consists of large number of people who are scattered all over the country. Due to its large size the members don't have personal relations among themselves.
(2) Difference in physical proximity:
Physical proximity refers to physical closeness or physical nearness. Members of a primary group are physically close to each other and personally known to each other. There exists a face-to-face contact among the members of a primary group. But in a secondary group the face-to-face contact is not found among the members. Physical distance is a characteristic feature of secondary group.
(3) Difference in relationship:
The relationship of the members of a primary group is primary relationship which are direct, personal, cordial, close, intimate, face-to-face and informal in nature. For example, family, play group, neighborhood etc. But, on the other hand, the relationship of the members of a secondary group is secondary relationship which are indirect, impersonal, formal, lacks face-to-face, lacks cordiality and less intimate. For example, political parties voluntary organisations, trade union etc.
(4) Difference in nature of control:
Primary group controls the behaviour of its members through informal means such as customs, traditions, folkways, mores, norms, beliefs, suggestions etc. Secondary groups control the behaviour of its members by formal means such as law, police, court, jail, army etc.
(5) Difference in goals:
The goals or the aims and objectives of the members of a primary group is same and the persons take other's interest as their own. The main purpose of a primary group is to fulfill all the needs of the members. But in secondary groups the aims or goal are not same. Every one ties to fulfill his self-interest. Secondary groups satisfy the specific need or interest of the members.
(6) Difference in means and ends:
Primary group is characterized by the primary relationship and this is not as a means to an end, but an end in itself. This relationship is spontaneous. On the other hand, the secondary relationship is considered not as an end in itself but as a means to an end.
(7) Difference in structure:
The structure of primary group is rigid and guided by some rigid informal means of customs, traditions, folkways, mores and norms. But the structure of secondary group is very flexible and regulated by a set of formal rules.
(8) Difference in membership:
The membership of a primary group is permanent and compulsory because man lives, grows and dies within it. But the membership of the secondary group is temporary and voluntary. People may join secondary groups according to their will, and also withdraw their membership at anytime without any reason. That is why secondary groups are known as 'Special Interest Groups'.
(9) Difference in type of co-operations:
In the primary groups the co-operation among the members is always direct and intimate. So the primary relations are inclusive. But in secondary groups there is only indirect type or co-operation among the members because the functions are based on division of labor and specialization of work.
(10) Difference in position:
In primary groups, the position or status of a person is fixed according to his birth, age and sex. For example, in family the position of father is based upon his birth, and age. But in secondary groups, the position of a person is determined by his roles. For example, in a trade union the position of the president depends upon the roles he plays in the union.