Self-determination theory is a theory of human motivation, development, and wellness, proposed by Edward L. Deci and Richard M. Ryan in 2008. The theory states that “the degrees to which basic psychological needs for autonomy, competence, and relatedness are supported versus thwarted affect both the type and strength of motivation” (1). The theory focuses on types of motivation, rather than just on degrees, and pays particular attention to autonomous motivation, controlled motivation and amotivation as predictors of performance and well-being.
Ryan, R. M., & Deci, E. L. (2000). “Self-determination theory and the facilitation of intrinsic motivation, social development, and well-being“. American Psychologist, 55, 68-78.