Although many people are not aware of it, social groups permeate society. They define roles and rules, and they give people a sense of belonging. Some social groups are easily recognised and clearly defined, whereas others are more subtle and difficult to recognise.
A social group can be defined as any two or more people in social interaction who share expectations and responsibilities to the group and who share a unifying characteristic or sense of purpose. The study of social groups is conducted by sociologists who analyse behaviour and interactions among people and show how these interactions shape societies.
There are two main types of social groups: primary and secondary. Primary groups are usually kinship based, though not necessarily, and they are long lasting. Secondary groups are larger, formal groups based on common interests, backgrounds, goals or roles. Some examples of secondary groups include clubs, communities, gangs, teams and platoons. While secondary groups can be long lasting, they can also quickly form and almost immediately disband, as is the case with mobs. Sometimes small groups of people within the secondary group will form a new primary group. For example, if two people from the same chess club choose to get married, they are still members of the secondary group, the chess club, but they are also now members of a new primary group, the family.
Social groups are organised by many different factors. There are age-based social groups, such as AARP, systems of tribal elders in some West African cultures and youth camps. There are also gender-based social groups, such as Girl Scouts and Boy Scouts, or fraternities and sororities. The type of social group organisation most people tend to think of is interest based, such as political parties, religious groups or hobby clubs. Organization of membership, expectations and leadership varies from group to group, and some groups are much more cohesive than others.
While social groups provide support and identity to people, there is also evidence that these groups can sometimes be hotspots for discrimination, prejudice and elitism. For example, if it is acceptable within the group to discriminate against a certain race, religion or lifestyle, members of the group will likely conform to fit this model of behaviour and remain within the group. Social Identity Theory, developed by Tajfel and Turner, says that people in a social group, the "in-group" will sometimes act at the expense of people not in the group, the "out-group" to save face and remain in the in-group. Not all social groups experience this, but many fall prey to this type of thinking.
Social groups exist to give people a sense of common identity and belonging. Social groups make accomplishing goals much easier and more efficient since a social group can bring people together to work on a task instead of each person working individually. Social groups provide a network of support for people and help give people a collective voice in society. An organised group with many members will typically get more attention than individuals; therefore grouping together to achieve goals is beneficial. Evolutionary speaking, humans probably first formed social groups because it was safer than being alone. The more people there are working together to protect a common interest, the more likely they are to succeed. This mentality, which developed early in the history of humanity, still holds true in modern society.