George Herbert Mead was a social psychologist who taught philosophy at the University of Chicago from 1894 until his unexpected death at age 68. Mead never published a book and wrote few major papers. Thus, most of what we know of him was pulled together after his death by students from collected notes.
Mead theorized that the mind and the self were developed as people interact with each other, sharing meaning through language and gestures. However, because any particular person might interpret the meaning of words or gestures differently, people might internalize different perceptions and meanings. This capacity to understand the symbol or meaning behind a word or a gesture made humans distinct from the animals. It also posed an understanding of humans and their behavior that ran counter to existing explanations where a particular action automatically caused a predictable reaction regardless of how the action was understood.
To explain further, Mead has one consider the game of chess. When the first player moves a game piece, it calls out a response from another person and the two players come to share some common meaning of what the act means. In order for the second player to move wisely, she must then take on the perspective or assume the role of the first player, while simultaneously considering what her own next move might be. Thus, the second person has the capacity to become an object to her self. By so doing, the anticipated response of the first person now becomes a stimulus for controlling one's own action, and the meaning of the first person's act has in some way become internalized as one's own experience.
The equivalent of the chess game may involve a much more complex exchange of words and acts. Still, the intent is to arouse in others either the same or an antagonistic response to that which they have aroused in themselves. Thus, Mead believed that each person in the game had to carry within themselves the attitude of everyone else playing the game, a concept that he called the "generalized other."
From this understanding, Mead developed his notion of the self-concept. Through identification with others and role taking whereby we see through another person's perspective, we come to carry within ourselves the attitudes of others. On the one hand, these shared meanings allow us to participate meaningfully in society. On the other hand, they create in us thoughts and feelings by which we evaluate ourselves according to the social expectations of these various groups. Mead described the self as an ongoing dialogue between the "me" and the "I." The "me" represented the internalizations of the generalized other, or to say it another way, the thoughts and feelings one had about oneself that came from the way she believed people in particular groups regarded her. The "I" represented the ability that a person had to select, create, or choose an individual response to these "me" representations.
Mead's social psychology thus provides a way of understanding how religion, ritual, and symbolism, as components of the "me," may become internalized and play a defining role in one's self-concept. However, since the "I" interprets the messages from the "me," a person exercises some choice in how or if to develop spiritually and in the meaning he gives to religious acts or thoughts. For example, two teenagers may be raised in the same religious home. Through identification with parents, one of them may internalize their parents' faith without really ever examining her beliefs. The other teen may rebel against their parents, develop a role different than the compliant child and come to a very different set of religious beliefs and associations. From Mead's perspective, religion serves us best not by providing clearly marked theology by which to deal with God, but rather by extending the social attitude of everyone belonging to the same group to the universe at large. The end result is a society built on something like perfect neighborliness.