The self-schema refers to a long lasting and stable set of memories that summarize a person's beliefs, experiences and generalizations about the self, in specific behavioral domains. A person may have a self-schema based on any aspect of themselves as a person, including physical characteristics (body image), personality traits and interests, as long as they consider that aspect of their self to be important to their own self-definition. When someone has a schema about themselves they hyper focus on a trait about themselves and believe what they say to themselves about that specific trait. A self schema can be good or bad depending on what that person talks to themselves about and in what kind of tone.
For example, someone will have a self-schema of extroversion if they think of themselves as extroverted and also believe that their extroversion is central to who they are. Their self-schema for extroversion may include general self-categorizations ("I am sociable."), beliefs about how they would act in certain situations ("At a party I would talk to lots of people") and also memories of specific past events ("On my first day at university I made lots of new friends").
General
The term schematic describes having a particular schema for a particular dimension. For instance, a person in a rock band at night would have a "rocker" schema. However, during the day, if he works as a salesperson, he would have a "salesperson" schema during that period of time. Schemas vary according to cultural background and other environmental factors.
Once people have developed a schema about themselves, there is a strong tendency for that schema to be maintained by a bias in what they attend to, in what they remember, and in what they are prepared to accept as true about themselves. In other words, the self-schema becomes self-perpetuating. The self-schema is then stored in long-term memory, which both facilitates and biases the processing of personally relevant information. Individuals who form a self-schema of a person with good exercise habits will then in return exercise more frequently.
Self-schemas vary from person to person because each individual has very different social and cultural life experiences. A few examples of self-schemas are: exciting or dull; quiet or loud; healthy or sickly; athletic or nonathletic; lazy or active; and geek or jock. If a person has a schema for "geek or jock," for example, he might think of himself as a bit of a computer geek and would possess a lot of information about that trait. Because of this, he would probably interpret many situations based on relevance to his being a computer geek.
Another person with the "healthy or sickly" schema might consider themselves a very health conscious person. Their concern with being healthy would then affect everyday decisions such as what groceries they buy, what restaurants they frequent, or how often they exercise. Women who are schematic on appearance exhibited worse body image, lower self-esteem, and more negative mood than did those who are aschematic on appearance.
The term aschematic means not having a schema for a particular dimension. This usually occurs when people are not involved with or concerned about a certain attribute. For example, if a person plans on being a musician, a self-schema in aeronautics will not apply to him; he is aschematic on aeronautics.
Childhood creation
Early in life, we are exposed to the idea of the self from our parents and other figures. We begin to take on a very basic self-schema, which is mostly limited to a "good child" or "bad child" schema—that is, we see ourselves in unambiguously positive or negative terms. It is in childhood that we begin to offer explanations for our actions, which reasoning creates the more complicated concept of the self: a child will begin to believe that the self caused their behaviors, deciding on what motivations to offer as explanations of behavior.