Functional Behavioral Analysis

Individuals with developmental disabilities who exhibit dangerous, disruptive, and problematic behaviors challenge the resources of practitioners and families. In these cases, a functional behavioral analysis (FBA) is recommended. An FBA is used to evaluate the behaviors of individuals that interfere with the acquisition of skills, personal independence, or satisfactory interpersonal relationships. An FBA is both a theoretical framework for understanding human behavior and a set of assessment procedures. When conducting FBAs, practitioners identify and describe the relationships between the unique characteristics of the student and the environmental variables that “trigger” and reinforce behavior. An FBA is a systematic process that results in the identification and description of those variables. The results of an FBA are then used as the basis for designing individually tailored behavior support plans that focus on both decreasing interfering behaviors and increasing socially meaningful replacement behaviors.

In the early 1980s, a dramatic shift in the conceptualization and assessment of interfering behaviors (e.g., self-injury, aggression, tantrum, opposition, stereotypy, property destruction, bolting, and rumination) emerged. Whereas traditional models of assessment (e.g., norm-referenced cognitive, adaptive behavior, behavior rating scales) are used to offer a diagnosis and/or to determine the referred individual’s eligibility for special education placement and/or clinical services, this emerging model of assessment emphasized the importance of determining the functions of behavior. For example, whereas a traditional model of assessment is useful for answering the following question: “Does the individual qualify for services?” a functional behavioral assessment is useful for answering the following questions: “Why does this student engage in interfering behaviors?” and “What individualized behavioral supports can we use to treat these behaviors?” Hundreds of empirical studies have demonstrated that individualized treatments based on the functions of behavior are more efficient and effective than treatments based on the form of behavior. Two or more individuals may display the same form of behavior (i.e., the same topography; the behavior looks the same), but the functions of these similar behaviors may be very different. For example, consider the case in which three individuals (John, George, and Paul) exhibit a similar behavior (e.g., physical aggression directed to staff in a group home). Further analysis yields that the specific functions of interfering behavior vary across individuals: (a) John’s behaviors are reinforced by avoidance of tasks, (b) George’s behaviors are maintained by social attention received from staff, and (c) Paul’s behaviors are reinforced by access to preferred activities. Although it may be tempting to develop one standard treatment to address the aggressive behaviors displayed by these three individuals, given that [Page 685]interventions matched to the functions of behaviors are more effective than those based on the form of behavior, the function-based interventions developed for each individual should be distinctly different.