Affect theory is a branch of psychoanalysis created by Sylvan Tompkins . Tompkins proposes that there are nine affects that produce responses and emotions in humans. These affects can be identified through immediate facial reactions that people have to a stimulus, typically well before they could process any real response to the stimulus.

Affect theory's use in psychoanalysis and therapy is limited, though it has gained widespread use in psychoanalytic theory, particularly through the work of Eve Sedgwick and Lauren Berlant, who have written extensively about affect.