Persons who have a strong sense of efficacy deploy their attention and effort to the demands of the situation and are spurred by obstacles to greater effort.
Albert Bandura (1982). "Self-efficacy mechanism in human agency". American Psychologist 37 (2): 122-147. ISSN 0003-066X. DOI:10.1037/0003-066X.37.2.122. (p. 123) (appears also in Bandura's Social Foundations of Thought and Action, 1986, p. 394)