The primary group are parents and two sisters.
This is known to be a group where a person can exchanges things, such as love, caring, concern, and others.
A voluntary group is also known to be a kind of group that a person willingly belongs to without been force. From the case above you can see that Joe loves to be with his friends. The opposite of voluntary group is involuntary group where one cannot leave even if they want to and an example is family.
Note therefore, the primary group are parents and two sisters.
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