Primary groups are pre-existing formations for an individual. Out of the following points used below, _______ is not a characteristic of primary groups.

individuals join by choice

The correct answer is Option (4) → individuals join by choice

Primary groups, such as family or close childhood friends, are typically pre-existing and not formed by deliberate choice. Their characteristics include:

– Close physical proximity
– Face-to-face interaction
– Less permeable boundaries (members are relatively fixed)

However, the statement "individuals join by choice" does not apply to primary groups, as people are usually born into them or become part of them early in life without active selection. 

A major difference between primary and secondary groups is that primary groups are pre-existing formations which are usually given to the individual whereas secondary groups are those which the individual joins by choice.