Sociological study relies on the ability to classify the people being studied in order to arrive at correct conclusions. Classifications include groups, aggregates, and categories.


A group consists of two or more people who are distinct in the following three ways:

  • Interact over time.
  • Have a sense of identity or belonging.
  • Have norms that nonmembers don’t have.

Example: A class of students is a group. Classes by definition consist of more than two people, meet at least a few times a week for an entire semester, and identify themselves on the basis of what classes they are taking. Students in a class must follow that professor’s class and test schedule, as well as rules for behavior and contribution in class.

Many different types of groups exist in industrialized societies, including school classes, social clubs, sports teams, neighborhood associations, religious communities, and volunteer organizations. Within any group, it is not uncommon for a few people to have an especially close relationship and form a clique, which is an internal cluster or faction within a group.


The word group is sometimes confused with the word aggregate. An aggregate is a collection of people who happen to be at the same place at the same time but who have no other connection to one another.

Example: The people gathered in a restaurant on a particular evening are an example of an aggregate, not a group. Those people probably do not know one another, and they’ll likely never again be in the same place at the same time.


A category is a collection of people who share a particular characteristic. They do not necessarily interact with one another and have nothing else in common.

Example: Categories of people might include people who have green eyes, people who were born in Nevada, and women who have given birth to twins.

Popular pages: Social Groups and Organizations