George Herbert Mead (1863-1931) was a social philosopher at the University of Chicago in the early 20th century. His work is considered to a (or even THE) foundation for the symbolic interactionist school of thought in sociology. His thinking is related to pragmatism and goes by the name "social behaviorism."
Mead uses the notion of a game and its players as an analogy for how human individuals must internalize the attitudes of all other members of their group in order to understand meaning, have a concept of self, and know how to act and react. The individual must take on the group’s attitude about himself and about everything else including other groups and their interaction. The development of the individual happens in two major parts: obtaining the attitudes of all other members of the group and then organizing those into “a generalized other”. This allows the individual to develop the fullest, most moral and self-conscious self. Our self-consciousness allows us to react to ourselves in terms of the responses of others. This allows groups and communities to function smoothly because all members share general attitudes “One has to be a member of a community to be a self” (Mead). [C McNaughton]
Source: Mead's most well known and influential work is Mind, Self, and Society.