Intrinsic motivation is the natural, inherent drive to seek out challenges and new possibilities that SDT associated with cognitive and social development.
Cognitive Evaluation Theory (CET) is a sub-theory of SDT that specifies factors explaining intrinsic motivation and variability with it and looks at how social and environmental factors help or hinder intrinsic motivations. CET focuses on the needs of competence and autonomy.
Claiming social context events like feedback on work or rewards lead to feelings of competence and so enhance intrinsic motivations. Deci found positive feedback enhanced intrinsic motivations and negative feedback diminished it. Vallerand and Reid went further and found that these effects were being mediated by perceived control.
Autonomy however must accompany competence in order for people to see their behaviours as self determined by intrinsic motivation. For this to happen there must be immediate contextual support for both needs or inner resources based on prior development support for both needs.
CET and intrinsic motivation is also linked to relatedness through the hypothesis that intrinsic motivation will flourish if linked with a sense of security and relatedness. Grolnick and Ryan found lower intrinsic motivation in children who believed their teachers to be uncaring or cold and so not fulfilling their relatedness needs.