A peer group is a social group whose members have interests, social positions and age in common. This is where children can escape supervision and learn to form relationships on their own. The influence of the peer group typically peaks during adolescence however peer groups generally only affect short term interests unlike the family which has long term influence.
While institutions tend to appear to people in society as part of the natural, unchanging landscape of their lives, study of institutions by the social sciences tends to reveal the nature of institutions as social constructions, artifacts of a particular time, culture and society, produced by collective human choice, though not directly by individual intention. Sociology traditionally analyzed social institutions in terms of interlocking social roles and expectations. Social institutions created and were composed of groups of roles, or expected behaviors. The social function of the institution was executed by the fulfillment of roles. Basic biological requirements, for reproduction and care of the young, are served by the institutions of marriage and family, for example, by creating, elaborating and prescribing the behaviors expected for husband/father, wife/mother, child, etc.
In the social sciences, a social group has been defined as two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity. Other theorists disagree however, and are wary of definitions which stress the importance of interdependence or objective similarity.Instead, researchers within the social identity tradition generally define it as “a group is defined in terms of those who identify themselves as members of the group”. Regardless, social groups come in a myriad of sizes and varieties. For example, a society can be viewed as a large social group.
A social group exhibits some degree of social cohesion and is more than a simple collection or aggregate of individuals, such as people waiting at a bus stop, or people waiting in a line. Characteristics shared by members of a group may include interests, values, representations, ethnic or social background, and kinship ties. Kinship ties being a social bond based on common ancestry, marriage, or adoption. In a similar vein, some researchers consider the defining characteristic of a group as social interaction. According to Dunbar’s number, on average, people cannot maintain stable social relationships with more than 150 individuals.