“Among the mechanisms of human agency, none is more central or pervasive than people's beliefs in their efficacy to influence events that affect their lives. This core belief is the foundation of human inspiration, motivation, performance accomplishments, and emotional well-being. Unless people believe they can produce desired effects by their actions, they have little incentive to undertake activities or to persevere in the face of difficulties. Whatever other factors serve as guides and motivators, they are rooted in the core belief that one has the power to affect changes by one's actions. This core belief operates through its impact on cognitive, motivational, affective, and decisional processes.”