Functional Analytic Psychotherapy (FAP) is a psychotherapy developed by Robert Kohlenberg and Mavis Tsai at the University of Washington. FAP is based on the behavior analytic, or functional contextualistic, approach to human behavior first described by B.F. Skinner. However, the treatment is not mechanistic; in fact, FAP results in psychotherapy relationships that are usually more intense and personal than is typically found in cognitive-behavioral treatments.