I've been reluctant to put up any sort of information about functional assessment because dealing appropriately, safely, and ethically with aggressive, self-injurious, or other undesirable behavior is one of the most important responsibilities of any behavior analyst. Obviously, and unfortunately, without meeting a student, I can't ethically or correctly advise what to do about a particular behavior. However, perhaps I can offer some ideas and resources to figure it out.

    First off, it's critical to have a good operational definition of the behavior. The behavior must be described exactly so that everyone is consistent in identifying it. Undesirable behavior almost always comes in the way of learning, as well as potentially being dangerous to the student, those around him, or to the environment. The first step, after ensuring that the student, those around him, and the environment are safe, is to determine the function of the behavior. All behavior has at least one function; behavior does not occur "out of the blue" or without reason. Identifying the function of the behavior is clearly the biggest obstacle, since without knowing that, a relevant and effective intervention cannot be identified and implemented.

    Here's some information that comes mainly from my knowledge of Brian Iwata's work on functional analysis. An online search for his name, especially in behavior analytic journals such as JABA (Journal of ABA), will yield more specific references.

    There are really only four classes of controlling variables for aggressive or self-injurious behavior:

° 1) Socially mediated positive reinforcement: This is what we often refer to as behavior of which "getting attention" is a function. It actually means that the behavior has been historically reinforced by the delivery of positive reinforcement by another person, so that when there is an MO/EO (desire) and an SD (antecedent stimulus) for this type of reinforcement, the behavior occurs.

° 2) Socially mediated negative reinforcement: This is what we often refer to as behavior of which escape and/or avoidance of demands is a function. It actually means that the behavior has been historically reinforced by the removal of aversive stimuli by another person, so that when there is an MO/EO and an SD for this type of reinforcement, the behavior occurs.

° 3) Automatic positive reinforcement: This is what we often refer to as stimming, or any behavior of which reinforcing sensory consequences is a function. It actually means that the behavior has been historically reinforced by the child himself, usually when there is only inadequate reinforcement from others available in the environment. As above, it requires an MO/EO and SD to occur.

° 4) Automatic negative reinforcement: This is usually an attempt by the child to remove pain or internal discomfort, such as an earache or headache. It should always be ruled in or out first to prevent time being wasted on behavior when medical attention is actually necessary.

    In order to determine the function of the behavior, it may be necessary to conduct a controlled "study" of sorts. I would really recommend getting the assistance of a trained professional with this, since it could be dangerous to attempt if a qualified person is not present to handle it. One would need to take data on the frequency of the student's tantrum behavior in each of four separate conditions:

° 1) Attention condition: In this condition, the teacher and student would be in a room with toys, games, or other reinforcing stimuli present. If any tantrum behavior occurred, pay a lot of attention to it, reacting to the child, saying, "Don't do that," etc. Only pay attention to the tantrums, not to any positive behavior. If the frequency of tantrums increased, you'd know attention (socially mediated positive reinforcement) was the function.

° 2) Demand condition: In this condition, the teacher and student would be in a room with only work materials present. Try to run instructional trials. If any tantrum behavior occurred, withdraw the demands until the behavior stopped. Then bring back demands again, removing them any time a tantrum occurred. If the frequency of tantrums increased, you'd know escape/avoidance (socially mediated negative reinforcement) was the function.

° 3) Alone condition: In this condition, the student would be alone in a room with no materials of any kind present, neither positive (reinforcers) nor aversive (demands). The room should be as empty as possible. If the frequency of tantrums increased, you'd know automatic positive reinforcement was the function.

° 4) Play condition: In this condition, the teacher and student would be in a room with toys, games, or other reinforcing stimuli present. Provide lots of attention and positive reinforcement noncontingently (not dependent upon anything your student did). If the frequency of tantrums increased, you'd know automatic negative reinforcement was the function, and that he should go to a doctor for an exam.


    Behavior may have one function or multiple functions. Studying the behavior scientifically is the only way to tease out what the functions are in what situations and, therefore, to determine the most appropriate and effective way to intervene.