Functional analysis constitutes a form of functional assessment that aims to identify the reasons (or “functions”) for behavior by engaging in a detailed analysis of the environment in which it occurs. Functional analysis is based on the principle that environmental stimuli determine behavior, and the reasons for its occurrence can be understood by analyzing the relationship between what triggered the behavior (its antecedents), the behavior itself, and the consequences of the behavior, as these can either reinforce it or decrease it. Once this behavioral chain is identified, it is possible to manipulate the antecedents or consequences and find which factors are sustaining the behavior through experimentation.
In psychotherapy, functional analysis is a tool that helps both therapist and client to identify and understand maladaptive behaviors and target the factors in the behavioral chain that need to be manipulated in order to promote behavioral change. This allows the consequent development of an effective intervention plan that is tailored to the individual's behavioral patterns.