Functional analysis (psychology)

Functional analysis in behavioral psychology is the application of the laws of operant and respondent conditioning to establish the relationships between stimuli and responses. To establish the function of operant behavior, one typically examines the "four-term contingency": first by identifying the motivating operations (EO or AO), then identifying the antecedent or trigger of the behavior, identifying the behavior itself as it has been operationalized, and identifying the consequence of the behavior which continues to maintain it.

Functional assessment in behavior analysis employs principles derived from the natural science of behavior analysis to determine the "reason", purpose, or motivation for a behavior. The most robust form of functional assessment is functional analysis, which involves the direct manipulation, using some experimental design (e.g., a multielement design or a reversal design) of various antecedent and consequent events and measurement of their effects on the behavior of interest; this is the only method of functional assessment that allows for demonstration of clear cause of behavior. Experimental functional analyses generally involve several conditions where the client is exposed to potential forms of reinforcement but one (e.g., the client is given social attention, no demands are placed on them, but they aren't given access to toys). If the behavior occurs more frequently in a given condition, the behavior's function is hypothesized to gain the absent form of reinforcement (e.g., yelling to gain social attention). Most functional analyses also involve a control condition where the client is given access to all potential forms of reinforcement. If the behavior occurs frequently in this condition, the behavior is hypothesized to be automatically reinforced i.e. the behavior itself is a source of reinforcement.