Psychological Review 1977, Vol. 84, No. 2, 191-215 Self-efficacy: Toward a Unifying Theory of Behavioral Change Albert Bandura Stanford University The present article presents an integrative theoretical framework to explain and to predict psychological changes achieved by different modes of treatment. This theory states that psychological procedures, whatever their form, alter the level and strength of self-efficacy. It is hypothesized that expectations of per- sonal efficacy determine whether coping behavior will be initiated, how much effort will be expended, and how long it will be sustained in the face of ob- stacles and aversive experiences. Persistence in activities that are subjectively threatening but in fact relatively safe produces, through experiences of mastery, further enhancement of self-efficacy and corresponding reductions in defensive behavior. In the proposed model, expectations of personal efficacy are derived from four principal sources of information: performance accomplishments, vicarious experience, verbal persuasion, and physiological states. The more de- pendable the experiential sources, the greater are the changes in perceived self- efficacy. A number of factors are identified as influencing the cognitive processing of efficacy information arising from enactive, vicarious, exhortative, and emotive sources. The differential power of diverse therapeutic procedures is analyzed in terms of the postulated cognitive mechanism of operation. Findings are reported from microanalyses of enactive, vicarious, and emotive modes of treatment that support the hypothesized relationship between perceived self-efficacy and be- havioral changes. Possible directions for further research are discussed. Current developments in the field of be- havioral change reflect two major divergent trends. The difference is especially evident in the treatment of dysfunctional inhibitions and defensive behavior. On the one hand, the mechanisms by which human behavior is acquired and regulated are increasingly for- mulated in terms of cognitive processes. On the other hand, it is performance-based pro- cedures that are proving to be most powerful for effecting psychological changes. As a con- sequence, successful performance is replacing symbolically based experiences as the prin- ciple vehicle of change. The present article presents the view that changes achieved by different methods derive from a common cognitive mechanism. The The research by the author reported in this article was supported by Research Grant M-5162 from the National Institutes of Health, United States Public Health Service. Requests for reprints should be sent to Albert Bandura, Department of Psychology, Stanford Uni- versity, Stanford, California 94305. apparent divergence of theory and practice can be reconciled by postulating that cogni- tive processes mediate change but that cog- nitive events are induced and altered most readily by experience of mastery arising from effective performance. The distinction be- tween process and means is underscored, be- cause it is often assumed that a cognitive mode of operation requires a symbolic means of induction. Psychological changes can be produced through other means than per- formance accomplishments. Therefore, the explanatory mechanism developed in this article is designed to account for changes in behavior resulting from diverse modes of treatment. Cognitive Locus of Operation Psychological treatments based on learning principles were originally conceptualized to operate through peripheral mechanisms. New behavior was presumably shaped automat- ically by its effects. Contingency learning through paired stimulation was construed in 191