Self-efficacy can be defined as individuals’ beliefs in their capability to implement a behavior needed to reach a goal or perform a task successfully. A vast amount of empirical research shows that self-efficacy is a key factor in predicting and explaining the successful initiation and maintenance of behavior change in various domains of human life. Less research has been conducted on the sources of self-efficacy (mastery experiences, vicarious experiences, verbal persuasion, somatic and affective states) and how these can be prompted in behavior change interventions. This chapter reviews primary and meta-analytic research on behavior change techniques promoting self-efficacy beliefs in interventions for change in health, work, and academic contexts. It also provides practical guidelines and concrete examples on how to design and evaluate behavior change interventions that target self-efficacy.

Social cognitive theory focuses on the reciprocal interaction of the person, environment, and behavior and provides a description of the ways in which individuals initiate and maintain behaviors, taking into consideration their social environment. The main operative constructs in the theory are outcome expectancies and self-efficacy. Outcome expectancies pertain to the anticipated consequences of one’s actions. Self-efficacy reflects a subjective estimate of the amount of personal control an individual expects to have in any given situation. The theory has been applied as a basis for changing behavior in a wide variety of disciplines and settings, including sport, education, career and occupational development, and mental and physical health settings. Interventions have targeted change in self-efficacy, outcome expectancies, or both, assuming that an improvement in these beliefs translates to changes in behavioral outcomes. A considerable body of evidence supporting theory predictions has accumulated. Research has underscored the beneficial effects of such interventions on target behaviors and outcomes such as academic achievement, career promotion, job search, smoking cessation, participation in physical exercise, and eating a healthy diet across a broad array of populations and settings. The theory has been influential in the development of other theories that have adopted parts of it, in particular, the self-efficacy construct.