Agency is the sense of control that you feel in your life, your capacity to influence your own thoughts and behavior, and have faith in your ability to handle a wide range of tasks and situations. Your sense of agency helps you to be psychologically stable, yet flexible in the face of conflict or change.
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In social science, agency is the capacity of individuals to have the power and resources to fulfill their potential. Social structure consists of those factors of influence (such as social class, religion, gender, ethnicity, ability, customs, etc.) that determine or limit agents and their decisions.