Bandura 1993

„There are several reasons why self-referent phenomena have come to pervade diverse areas of psychology. Self influences affect the selection and construction of environments. The impact of most environmental influences on human motivation, affect, and action is heavily mediated through self processes. They give meaning and valence to external events. Self influences thus operate as important proximal determinants at the very heart of causal processes.
People make causal contributions to their own functioning through mechanisms of personal agency. Among the mechanisms of agency, none is more central or pervasive than people's beliefs about their capabilities to exercise control over their own level of functioning and over events that affect their lives. Efficacy beliefs influence how people feel, think, motivate themselves, and behave. Self-efficacy beliefs produce these diverse effects through four major processes (A. Bandura, 1992). They include cognitive, motivational, affective, and selection processes. Bach of these processes is analyzed in the sections that follow.

The effects of self-efficacy beliefs on cognitive processes take a variety of forms. Much human behavior, which is purposive, is regulated by forethought embodying cognized goals. Personal goal setting is influenced by self-appraisal of capabilities. The stronger the perceived self-efficacy, the higher the goal challenges people set for themselves and the firmer is their commitment to them (A. Bandura, 1991).
Most courses of action are initially shaped in thought. People's beliefs in their efficacy influence the types of anticipatory scenarios they construct and rehearse. Those who have a high sense of efficacy visualize success scenarios that provide positive guides and supports for performance. Those who doubt their efficacy visualize failure scenarios and dwell on the many things that can go wrong. lt is difficult to achieve much while fighting self-doubt.
The conception of human ability has undergone considerable change in recent years. Ability is not a fixed attribute residing in one's behavioral repertoire. Rather, it is a generative capability in which cognitive, social, motivational, and behavioral skills must be organized and effectively orchestrated to serve numerous purposes. lt also involves skill in managing aversive emotional reactions that can impair the quality of thinking and action. There is a marked difference between possessing knowledge and skills and being able to use them well under taxing conditions. Personal accomplishments require not only skills but self-beliefs of efficacy to use them well. Hence, a person with the same knowledge and skills may perform poorly, adequately, or extraordinarily depending on fluctuations in self-efficacy thinking.“

Aus: Bandura, A. (1993) Perceived Self-Efficacy in Cognitive Development and Functioning