Self-Efficacy
Ralf Schwarzer, Freie Universitat Berlin, Germany ,
and Aleksandra Luszczynska, University of Sussex, UK

Most prominent health behavior theories include self-efficacy (or similar constructs). Self-efficacy is a proximal and direct predictor of intention and of behavior. According to Social Cognitive Theory (SCT; Bandura, 1997 xClose
Bandura, A. (1997). Self-efficacy: The exercise of control. New York: Freeman. ), a personal sense of control facilitates a change of health behavior. Self-efficacy pertains to a sense of control over one's environment and behavior. Self-efficacy beliefs are cognitions that determine whether health behavior change will be initiated, how much effort will be expended, and how long it will be sustained in the face of obstacles and failures. Self-efficacy influences the effort one puts forth to change risk behavior and the persistence to continue striving despite barriers and setbacks that may undermine motivation. Self-efficacy is directly related to health behavior, but it also affects health behaviors indirectly through its impact on goals. Self-efficacy influences the challenges that people take on as well as how high they set their goals (e.g., "I intend to reduce my smoking," or "I intend to quit smoking altogether"). Individuals with strong self-efficacy select more challenging goals (DeVellis & DeVellis, 2000 xClose
DeVellis, B. M., & DeVellis, R. F. (2000). Self-efficacy and health. In: A. Baum, T. A. Revenson, & J. E. Singer (Eds.), Handbook of Health Psychology (pp. 235-247). Mahwah, NJ: Erlbaum. ). They focus on opportunities, not on obstacles (e.g., "At my university there is a smoking ban, anyway," instead of "There are still a lot of ashtrays at my university.").

According to the Theory of Planned Behavior (TPB; Ajzen, 1991 xClose
Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Human Decision Processes, 50, 179-211. ), intention is the most proximal predictor of behavior. Cognitions that affect a specific intention are attitudes, subjective norms, and perceived behavioral control (perception about being able to perform a specific behavior). A typical item to assess perceived behavioral control is, "It is easy for me to do xy." Self-efficacy and behavioral control are seen as almost synonymous constructs. However, self-efficacy is more precisely related to one's competence and to future behavior.

According to the Transtheoretical Model (TTM; Prochaska, Norcross, Fowler, Follick, & Abrams, 1992 xClose
Prochaska, J. O., Norcross, J. C., Fowler, J., Follick, M. J., & Abrams, D. B. (1992). Attendance and outcome in a worksite weight control program: Processes and stages of change as process and predictor variables. Addictive Behaviors, 17, 35-45. ), self-efficacy and perceived positive ("pros") and negative ("cons") outcomes are seen as the main social-cognitive variables that change across the stages. Self-efficacy is typically low in early stages and increases when individuals move on to the later stages. For a critical discussion of this model, see Sutton (2005) xClose
Sutton, S. (2005). Stage theories of health behavior. In M. Conner & P. Norman (Eds.), Predicting health behaviors. (2nd ed., pp. 223-275). Maidenhead, England: Open University Press. and West (2005) xClose
West, R. (2005). What does it take for a theory to be abandoned? The transtheoretical model of behaviour change as a test case. Addiction, 100, 1048-1050. .

The Health Action Process Approach (Schwarzer, 1992 xClose
Schwarzer, R. (1992). Self-efficacy in the adoption and maintenance of health behaviors: Theoretical approaches and a new model. In R. Schwarzer (Ed.), Self-efficacy: Thought control of action (pp. 217-243). Washington, DC: Hemisphere. , 2001 xClose
Schwarzer, R. (2001). Social-cognitive factors in changing health-related behavior. Current Directions in Psychological Science, 10, 47-51. ) argues for a distinction between (a) preintentional motivation processes that lead to a behavioral intention and (b) post-intentional volition processes that lead to actual health behavior. In the motivation phase, one needs to believe in one's capability to perform a desired action ("I am capable of initiating a healthier diet in spite of temptations"), otherwise one will fail to initiate that action. In the subsequent volition phase, after a person has developed an inclination toward adopting a particular health behavior, the "good intention" has to be transformed into detailed instructions on how to perform the desired action. Self-efficacy influences the processes of planning, taking initiative, maintaining behavior change, and managing relapses (see Luszczynska & Schwarzer, 2003 xClose
Luszczynska, A., & Schwarzer, R. (2005). Multidimensional health locus of control: Comments on the construct and its measurement. Journal of Health Psychology, 10, 633-642. ; Marlatt, Baer, & Quigley, 1995 xClose
Marlatt, G. A., Baer, J. S., & Quigley, L. A. (1995). Self-efficacy and addictive behavior. In A. Bandura (Ed), Self-efficacy in changing societies (pp. 289-315). New York: Cambridge University Press. ). For a critical discussion, see Sutton (2005) xClose
Sutton, S. (2005). Stage theories of health behavior. In M. Conner & P. Norman (Eds.), Predicting health behaviors. (2nd ed., pp. 223-275). Maidenhead, England: Open University Press. .

There are a few studies that have compared the predictive power of constructs derived from different theories. Dzewaltowski (1989) xClose
Dzewaltowski, D. A. (1989). Toward a model of exercise motivation. Journal of Sport and Exercise Psychology, 11, 251-269. compared the predictive utility of the Theory of Reasoned Action (TRA) and SCT in the field of exercise motivation. The exercise behavior of students was recorded and then related to prior measures of different cognitive factors. The variables from TRA predicted exercise behavior. In addition, strength of self-efficacy, expected outcomes and satisfaction with level of activities were assessed. Individuals who were confident that they could adhere to the strenuous exercise program, who were dissatisfied with their present level of physical activity, and who expected positive outcomes also exercised more. TRA variables did not account for any unique variance in exercise behavior after controlling for the social cognitive factors. These findings indicate that SCT provides powerful explanatory constructs. Other studies using constructs from different theories also show that the effects of self-efficacy on physical activity are stronger than those of other psychosocial determinants (see Rovniak, Anderson, Winett, & Stephens, 2002 xClose
Rovniak, L. S., Anderson, E. S., Winett, R. A., & Stephens, R. S. (2002). Social cognitive determinants of physical activity in young adults: A prospective structural equation analysis. Annals of Behavioral Medicine, 24, 149-156. ).