Self-efficacy is the extent or strength of one's belief in one's own ability to complete tasks and reach goals. Psychologists have studied self-efficacy from several perspectives, noting various paths in the development of self-efficacy; the dynamics of self-efficacy, and lack thereof, in many different settings; interactions between self-efficacy and self-concept; and habits of attribution that contribute to, or detract from, self-efficacy.
This can be seen as the ability to persist and a person's ability to succeed with a task. As an example, self-efficacy directly relates to how long someone will stick to a workout regimen or a diet. High and low self-efficacy determine whether or not someone will choose to take on a challenging task or write it off as impossible.
Self-efficacy affects every area of human endeavor. By determining the beliefs a person holds regarding his or her power to affect situations, it strongly influences both the power a person actually has to face challenges competently and the choices a person is most likely to make. These effects are particularly apparent, and compelling, with regard to behaviors affecting health.
Psychologist Albert Bandura has defined self-efficacy as one's belief in one's ability to succeed in specific situations. One's sense of self-efficacy can play a major role in how one approaches goals, tasks, and challenges. The theory of self-efficacy lies at the center of Bandura’s social cognitive theory, which emphasizes the role of observational learning and social experience in the development of personality. The main concept in social cognitive theory is that an individual’s actions and reactions, including social behaviors and cognitive processes, in almost every situation are influenced by the actions that individual has observed in others. Because self-efficacy is developed from external experiences and self-perception and is influential in determining the outcome of many events, it is an important aspect of social cognitive theory. Self-efficacy represents the personal perception of external social factors. According to Bandura's theory, people with high self-efficacy—that is, those who believe they can perform well—are more likely to view difficult tasks as something to be mastered rather than something to be avoided.
Social learning theory describes the acquisition of skills that are developed exclusively or primarily within a social group. Social learning depends on how individuals either succeed or fail at dynamic interactions within groups, and promotes the development of individual emotional and practical skills as well as accurate perception of self and acceptance of others. According to this theory, people learn from one another through observation, imitation, and modeling. Self-efficacy reflects an individual’s understanding of what skills he/she can offer in a group setting.
Self-concept theory seeks to explain how people perceive and interpret their own existence from clues they receive from external sources, focusing on how these impressions are organized and how they are active throughout life. Successes and failures are closely related to the ways in which people have learned to view themselves and their relationships with others. This theory describes self-concept as learned (i.e., not present at birth); organized (in the way it is applied to the self); and dynamic (i.e., ever-changing, and not fixed at a certain age). 
Attribution theory focuses on how people attribute events and how those beliefs interact with self-perception. Attribution theory defines three major elements of cause:
Locus is the location of the perceived cause. If the locus is internal (dispositional), feelings of self-esteem and self-efficacy will be enhanced by success and diminished by failure.
Stability describes whether the cause is perceived as static or dynamic over time. It is closely related to expectations and goals, in that when people attribute their failures to stable factors such as the difficulty of a task, they will expect to fail in that task in the future.
Controllability describes whether a person feels actively in control of the cause. Failing at a task one thinks one cannot control can lead to feelings of humiliation, shame, and/or anger
How it affects human function
Choices regarding behavior
People generally avoid tasks where self-efficacy is low, but undertake tasks where self-efficacy is high. When self-efficacy is significantly beyond actual ability, it leads to an overestimation of the ability to complete tasks. On the other hand, when self-efficacy is significantly lower than actual ability, it discourages growth and skill development. Research shows that the optimum level of self-efficacy is slightly above ability; in this situation, people are most encouraged to tackle challenging tasks and gain experience.
High self-efficacy can affect motivation in both positive and negative ways. In general, people with high self-efficacy are more likely to make efforts to complete a task, and to persist longer in those efforts, than those with low self-efficacy. The stronger the self-efficacy or mastery expectations, the more active the efforts. However, those with low self-efficacy sometimes experience incentive to learn more about an unfamiliar subject, where someone with a high self-efficacy may not prepare as well for a task.
Thought patterns & responses
Self-efficacy has several effects on thought patterns and responses:
Low self-efficacy can lead people to believe tasks to be harder than they actually are. This often results in poor task planning, as well as increased stress.
People become erratic and unpredictable when engaging in a task in which they have low self-efficacy.
People with high self-efficacy tend to take a wider view of a task in order to determine the best plan.
Obstacles often stimulate people with high self-efficacy to greater efforts, where someone with low self-efficacy will tend toward discouragement and giving up.
A person with high self-efficacy will attribute failure to external factors, where a person with low self-efficacy will blame low ability. For example, someone with high self-efficacy in regards to mathematics may attribute a poor test grade to a harder-than-usual test, illness, lack of effort, or insufficient preparation. A person with a low self-efficacy will attribute the result to poor mathematical ability. See Attribution Theory.
Choices affecting health, such as smoking, physical exercise, dieting, condom use, dental hygiene, seat belt use, and breast self-examination, are dependent on self-efficacy. 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 how high people set their health goals (e.g., "I intend to reduce my smoking," or "I intend to quit smoking altogether"). A number of studies on the adoption of health practices have measured self-efficacy to assess its potential to initiate behavior change.
Research on Australian science students showed that those with high self-efficacy showed better academic performance than those with low self-efficacy. Confident individuals typically took control over their own learning experiences, were more likely to participate in class, and preferred hands-on learning experiences. Those with low self-efficacy typically shied away from academic interactions.
Bandura showed that difference in self-efficacy correlates to fundamentally different world views. People with high self-efficacy generally believe that they are in control of their own lives, that their own actions and decisions shape their lives, while people with low self-efficacy may see their lives as outside their control.
Factors affecting self-efficacy
Bandura identifies four factors affecting self-efficacy.
1. Experience, or "Enactive Attainment"
The experience of mastery is the most important factor determining a person's self-efficacy. Success raises self-efficacy, while failure lowers it.
"Children cannot be fooled by empty praise and condescending encouragement. They may have to accept artificial bolstering of their self-esteem in lieu of something better, but what I call their accruing ego identity gains real strength only from wholehearted and consistent recognition of real accomplishment, that is, achievement that has meaning in their culture." (Erik Erikson)
Modeling is experienced as, "If they can do it, I can do it as well." When we see someone succeeding, our own self-efficacy increases; where we see people failing, our self-efficacy decreases. This process is most effectual when we see ourselves as similar to the model. Although not as influential as direct experience, modeling is particularly useful for people who are particularly unsure of themselves.
3. Social Persuasion
Social persuasion generally manifests as direct encouragement or discouragement from another person. Discouragement is generally more effective at decreasing a person's self-efficacy than encouragement is at increasing it.
4. Physiological Factors
In stressful situations, people commonly exhibit signs of distress: shakes, aches and pains, fatigue, fear, nausea, etc. Perceptions of these responses in oneself can markedly alter self-efficacy. Getting 'butterflies in the stomach' before public speaking will be interpreted by someone with low self-efficacy as a sign of inability, thus decreasing self-efficacy further, where high self-efficacy would lead to interpreting such physiological signs as normal and unrelated to ability. It is one's belief in the implications of physiological response that alters self-efficacy, rather than the physiological response itself.
Theoretical models of behavior
A theoretical model of the effect of self-efficacy on transgressive behavior was developed and verified in research with school children.
Prosociality and moral disengagement
Prosocial behavior (such as helping others, sharing, and being kind and cooperative) and moral disengagement (manifesting in behaviors such as making excuses for bad behavior, avoiding responsibility for consequences, and blaming the victim) are negatively correlated. Academic, social, and self-regulatory self-efficacy encourages prosocial behavior, and thus helps prevent moral disengagement. 
Over-efficaciousness in learning
In certain circumstances, lower self-efficacy can be helpful. One study examined foreign language students' beliefs about learning, goal attainment, and motivation to continue with language study. It was concluded that over-efficaciousness negatively affected student motivation, so that students who believed they were "good at languages" had less motivation to study.
Health behavior change
Social-cognitive models of health behavior change cast self-efficacy as predictor, mediator, or moderator. As a predictor, self-efficacy is supposed to facilitate the forming of behavioral intentions, the development of action plans, and the initiation of action. As mediator, self-efficacy can help prevent relapse to unhealthy behavior. As a moderator, self-efficacy can support the translation of intentions into action. See Health Action Process Approach.
Parents' sense of academic efficacy for their child is linked to their children's scholastic achievement. If the parents have higher perceived academic capabilities and aspirations for their child, the child itself will share those same beliefs. This promotes academic self-efficacy for the child, and in turn, leads to scholastic achievement. It also leads to prosocial behavior, and reduces vulnerability to feelings of futility and depression. There is a relationship between low self-efficacy and depression.
Self-efficacy theory has been applied to the career area to examine why women are underrepresented in male-dominated STEM fields such as mathematics, engineering, and science. It was found that gender differences in self-efficacy expectancies importantly influence the career-related behaviors and career choices of young women.
In a study, the majority of a group of students questioned felt they had a difficulty with listening in class situations. Instructors then helped strengthen their listening skills by making them aware about how the use of different strategies could produce better outcomes. This way, their levels of self-efficacy were improved as they continued to figure out what strategies worked for them.
At the National Kaohsiung First University of Science and Technology in Taiwan, researchers investigated the correlations between general Internet self-efficacy (GISE), Web-specific self-efficacy (WSE), and e-service usage. Researchers concluded that GISE directly affects the WSE of a consumer, which in turn shows a strong correlation with e-service usage. These findings are significant for future consumer targeting and marketing.
While self-efficacy is sometimes measured as a whole, as with the General Self-Efficacy Scale, it is also measured in particular functional situations.
Social self-efficacy has been variably defined and measured. According to Smith and Betz, social self-efficacy is "an individual’s confidence in her/his ability to engage in the social interactional tasks necessary to initiate and maintain interpersonal relationships." They measured social self-efficacy using an instrument of their own devise called the Scale of Perceived Social Self-Efficacy, which measured six domains: (1) making friends, (2) pursuing romantic relationships, (3) social assertiveness, (4) performance in public situations, (5) groups or parties, and (6) giving or receiving help.
Matsushima and Shiomi measured self-efficacy by focusing on self-confidence about social skill in personal relationship, trust in friends, and trust by friends.
Both groups of researchers suggest that social self-efficacy is strongly correlated with shyness and social anxiety.
Academic self-efficacy refers to the belief that one can successfully engage in and complete course-specific academic tasks, such as accomplishing course aims, satisfactorily completing assignments, achieving a passing grade, and meeting the requirements to continue to pursue one's major course of study. Various empirical inquiries have been aimed at measuring academic self-efficacy.
Self-efficacy versus efficacy. Unlike efficacy, which is the power to produce an effect—in essence, competence—the term self-efficacy is used, by convention, to refer to the belief (accurate or not) that one has the power to produce that effect by completing a given task or activity related to that competency. Self-efficacy is the belief in one's efficacy.
Self-efficacy versus self-esteem. Self-efficacy is the perception of one's own ability to reach a goal; self-esteem is the sense of self-worth. For example, a person who is a terrible rock climber would probably have poor self-efficacy with regard to rock climbing, but this will not affect self-esteem if the person doesn’t rely on rock climbing to determine self-worth. On the other hand, one might have enormous confidence with regard to rock climbing, yet set such a high standard, and base enough of self-worth on rock-climbing skill, that self-esteem is low. Someone who has high self-efficacy in general but is poor at rock climbing might have misplaced confidence, or believe that improvement is possible.
Self-efficacy versus confidence. According to Albert Bandura, "the construct of self-efficacy differs from the colloquial term 'confidence.' Confidence is a nonspecific term that refers to strength of belief but does not necessarily specify what the certainty is about. I can be supremely confident that I will fail at an endeavor. Perceived self-efficacy refers to belief in one's agentive capabilities, that one can produce given levels of attainment. A self-efficacy belief, therefore, includes both an affirmation of a capability level and the strength of that belief. Confidence is a catchword rather than a construct embedded in a theoretical system."
Self-efficacy versus self-concept. Self-efficacy comprises beliefs of personal capability to perform specific actions. Self-concept is measured more generally and includes the evaluation of such competence and the feelings of self-worth associated with the behaviors in question.
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