Functional analytic psychotherapy (FAP) is a psychotherapeutic approach based on clinical behavior analysis (CBA) that focuses on the therapeutic relationship as a means to maximize client change. Specifically, FAP suggests that in-session contingent responding to client target behaviors leads to significant therapeutic improvements.
FAP was first conceptualized in the 1980s by psychologists Robert Kohlenberg and Mavis Tsai who, after noticing a clinically significant association between client outcomes and the quality of the therapeutic relationship, set out to develop a theoretical and psychodynamic model of behavioral psychotherapy based on these concepts. Behavioral principles (e.g., reinforcement, generalization) form the basis of FAP.[1][2] (See § The five rules below.)
FAP is an idiographic (as opposed to nomothetic) approach to psychotherapy. This means that FAP therapists focus on the function of a client's behavior instead of the form. The aim is to change a broad class of behaviors that might look different on the surface but all serve the same function. It is idiographic in that the client and therapist work together to form a unique clinical formulation of the client's therapeutic goals, rather than one therapeutic target for every client who enters therapy.