Social cognitive theory has developed from social learning theory. It shares many fundamental principles with social learning theory but extends beyond it in its reliance on sociocognitive processes. This emphasis on sociocognitive processes has contributed to the explanatory value of the theory. It also has a broad focus that encompasses personal, environmental, and behavioral factors across the life span, which makes it one of the more comprehensive theories of human functioning. Central to the theory is human agency. This entry provides a description of the key social cognitive theory concepts and how they vary across the life span.